diff --git a/src/commands/DragCommand.cpp b/src/commands/DragCommand.cpp
index 920def2c2..638655a7c 100644
--- a/src/commands/DragCommand.cpp
+++ b/src/commands/DragCommand.cpp
@@ -97,6 +97,7 @@ bool DragCommand::Apply(const CommandContext & context)
    pWin->GetEventHandler()->ProcessEvent( Evt );
    if( bHasToX ){
       wxMouseEvent Evt2( wxEVT_LEFT_DOWN );
+      Evt2.m_leftDown = true;
       Evt2.m_x = mFromX;
       Evt2.m_y = mFromY;
       Evt2.m_aux2Down = true;
diff --git a/src/commands/GetInfoCommand.cpp b/src/commands/GetInfoCommand.cpp
index 45e2dba3f..a97e851f4 100644
--- a/src/commands/GetInfoCommand.cpp
+++ b/src/commands/GetInfoCommand.cpp
@@ -310,7 +310,7 @@ bool GetInfoCommand::SendEnvelopes(const CommandContext &context)
             context.StartField( "points" );
             context.StartArray();
             double offset = pEnv->mOffset;
-            for( int k=0;k<pEnv->mEnv.size(); k++)
+            for( size_t k=0;k<pEnv->mEnv.size(); k++)
             {
                context.StartStruct( );
                context.AddItem( pEnv->mEnv[k].GetT()+offset, "t" );
diff --git a/src/commands/OpenSaveCommands.cpp b/src/commands/OpenSaveCommands.cpp
index d5d261990..1ce167544 100644
--- a/src/commands/OpenSaveCommands.cpp
+++ b/src/commands/OpenSaveCommands.cpp
@@ -24,7 +24,7 @@
 
 bool OpenProjectCommand::DefineParams( ShuttleParams & S ){
    S.Define( mFileName, wxT("Filename"),  "test.aup" );
-   S.Define( mbAddToHistory, wxT("AddToHistory"),  false );
+   S.OptionalN(bHasAddToHistory).Define( mbAddToHistory, wxT("AddToHistory"),  false );
    return true;
 }
 
@@ -62,8 +62,8 @@ bool OpenProjectCommand::Apply(const CommandContext & context){
 
 bool SaveProjectCommand::DefineParams( ShuttleParams & S ){
    S.Define( mFileName, wxT("Filename"),  "name.aup" );
-   S.Define( mbAddToHistory, wxT("AddToHistory"),  false );
-   S.Define( mbCompress, wxT("Compress"),  false );
+   S.OptionalN(bHasAddToHistory).Define( mbAddToHistory, wxT("AddToHistory"),  false );
+   S.OptionalN(bHasCompress).Define( mbCompress, wxT("Compress"),  false );
    return true;
 }
 
diff --git a/src/commands/OpenSaveCommands.h b/src/commands/OpenSaveCommands.h
index 41798d3e9..9770b3749 100644
--- a/src/commands/OpenSaveCommands.h
+++ b/src/commands/OpenSaveCommands.h
@@ -38,6 +38,7 @@ public:
 public:
    wxString mFileName;
    bool mbAddToHistory;
+   bool bHasAddToHistory;
 };
 
 #define SAVE_PROJECT_PLUGIN_SYMBOL XO("Save Project")
@@ -58,4 +59,6 @@ public:
    wxString mFileName;
    bool mbAddToHistory;
    bool mbCompress;
+   bool bHasAddToHistory;
+   bool bHasCompress;
 };
\ No newline at end of file
diff --git a/src/commands/PreferenceCommands.cpp b/src/commands/PreferenceCommands.cpp
index 11f97db4a..fa2671aaa 100644
--- a/src/commands/PreferenceCommands.cpp
+++ b/src/commands/PreferenceCommands.cpp
@@ -50,9 +50,9 @@ bool GetPreferenceCommand::Apply(const CommandContext & context)
 }
 
 bool SetPreferenceCommand::DefineParams( ShuttleParams & S ){
-   S.Define( mName,    wxT("Name"),    wxT("") );
-   S.Define( mValue,   wxT("Value"),   wxT("") );
-   S.Define( mbReload, wxT("Reload"),  false );
+   S.Define(                       mName,    wxT("Name"),    wxT("") );
+   S.Define(                       mValue,   wxT("Value"),   wxT("") );
+   S.OptionalN(bHasReload).Define( mbReload, wxT("Reload"),  false );
    return true;
 }
 
diff --git a/src/commands/PreferenceCommands.h b/src/commands/PreferenceCommands.h
index fba717242..c53e520df 100644
--- a/src/commands/PreferenceCommands.h
+++ b/src/commands/PreferenceCommands.h
@@ -63,6 +63,7 @@ public:
    wxString mName;
    wxString mValue;
    bool mbReload;
+   bool bHasReload;
 };
 
 #endif /* End of include guard: __PREFERENCE_COMMANDS__ */
diff --git a/src/commands/ScreenshotCommand.cpp b/src/commands/ScreenshotCommand.cpp
index 4984e5edd..dcbd95263 100644
--- a/src/commands/ScreenshotCommand.cpp
+++ b/src/commands/ScreenshotCommand.cpp
@@ -139,9 +139,9 @@ static const wxString kBackgroundStrings[nBackgrounds] =
 bool ScreenshotCommand::DefineParams( ShuttleParams & S ){ 
    wxArrayString whats(nCaptureWhats, kCaptureWhatStrings);
    wxArrayString backs(nBackgrounds, kBackgroundStrings);
-   S.Define(     mPath, wxT("Path"),         wxT(""),       wxT(""), wxT(""), wxT(""));
-   S.DefineEnum( mWhat, wxT("CaptureWhat"),  wxT("Window"), whats );
-   S.DefineEnum( mBack, wxT("Background"),   wxT("None"), backs );
+   S.Define(                               mPath, wxT("Path"),         wxT(""));
+   S.DefineEnum(                           mWhat, wxT("CaptureWhat"),  wxT("Window"), whats );
+   S.OptionalN(bHasBackground).DefineEnum( mBack, wxT("Background"),   wxT("None"), backs );
    return true;
 };
 
@@ -154,8 +154,8 @@ void ScreenshotCommand::PopulateOrExchange(ShuttleGui & S)
    S.StartMultiColumn(2, wxALIGN_CENTER);
    {
       S.TieTextBox( _("Path:"), mPath);
-      S.TieChoice( _("Capture What:"), mWhat, &whats);
-      S.TieChoice( _("Background:"), mBack, &backs);
+      S.TieChoice(  _("Capture What:"), mWhat, &whats);
+      S.TieChoice(  _("Background:"), mBack, &backs);
    }
    S.EndMultiColumn();
 }
@@ -483,7 +483,8 @@ void ScreenshotCommand::CaptureWindowOnIdle(
 void ScreenshotCommand::CapturePreferences( 
    const CommandContext & context,
    AudacityProject * pProject, const wxString &mFileName ){
-   mFileName;//compiler food.
+   (void)&mFileName;//compiler food.
+   (void)&context;
    CommandManager * pMan = pProject->GetCommandManager();
 
    // Yucky static variables.  Is there a better way?  The problem is that we need the
@@ -512,7 +513,8 @@ void ScreenshotCommand::CapturePreferences(
 void ScreenshotCommand::CaptureEffects( 
    const CommandContext & context,
    AudacityProject * pProject, const wxString &mFileName ){
-   mFileName;//compiler food.
+   (void)&mFileName;//compiler food.
+   (void)&context;
    CommandManager * pMan = pProject->GetCommandManager();
    wxString Str;
    // Yucky static variables.  Is there a better way?  The problem is that we need the
diff --git a/src/commands/ScreenshotCommand.h b/src/commands/ScreenshotCommand.h
index cfdb47495..53ad6f41f 100644
--- a/src/commands/ScreenshotCommand.h
+++ b/src/commands/ScreenshotCommand.h
@@ -46,6 +46,7 @@ private:
    wxString mWhat;
    wxString mBack;
    wxString mPath;
+   bool bHasBackground;
    friend class ScreenshotCommand;
    friend class ScreenFrame;
 
diff --git a/src/commands/SelectCommand.cpp b/src/commands/SelectCommand.cpp
index 5fe0b6b12..bfc76ca8c 100644
--- a/src/commands/SelectCommand.cpp
+++ b/src/commands/SelectCommand.cpp
@@ -40,9 +40,9 @@ explicitly code all three.
 #include "CommandContext.h"
 
 bool SelectTimeCommand::DefineParams( ShuttleParams & S ){
-   S.Optional( bHasT0 ).Define( mT0, wxT("Start"), 0.0, 0.0, (double)FLT_MAX);
-   S.Optional( bHasT1 ).Define( mT1, wxT("End"), 0.0, 0.0, (double)FLT_MAX);
-   S.Define( mFromEnd, wxT("FromEnd"),   false );
+   S.OptionalY( bHasT0     ).Define( mT0, wxT("Start"), 0.0, 0.0, (double)FLT_MAX);
+   S.OptionalY( bHasT1     ).Define( mT1, wxT("End"), 0.0, 0.0, (double)FLT_MAX);
+   S.OptionalY( bHasFromEnd).Define( mFromEnd, wxT("FromEnd"),   false );
    return true;
 }
 
@@ -58,6 +58,7 @@ void SelectTimeCommand::PopulateOrExchange(ShuttleGui & S)
    S.EndMultiColumn();
    S.StartMultiColumn(2, wxALIGN_CENTER);
    {
+      // Always used, so no optional checkbox.
       S.TieCheckBox(_("From End:"), mFromEnd );
    }
    S.EndMultiColumn();
@@ -81,8 +82,8 @@ bool SelectTimeCommand::Apply(const CommandContext & context){
 }
 
 bool SelectFrequenciesCommand::DefineParams( ShuttleParams & S ){
-   S.Optional( bHasTop ).Define(    mTop,    wxT("High"), 0.0, 0.0, (double)FLT_MAX);
-   S.Optional( bHasBottom ).Define( mBottom, wxT("Low"),  0.0, 0.0, (double)FLT_MAX);
+   S.OptionalN( bHasTop ).Define(    mTop,    wxT("High"), 0.0, 0.0, (double)FLT_MAX);
+   S.OptionalN( bHasBottom ).Define( mBottom, wxT("Low"),  0.0, 0.0, (double)FLT_MAX);
    return true;
 }
 
@@ -121,9 +122,9 @@ static const wxString kModes[nModes] =
 
 bool SelectTracksCommand::DefineParams( ShuttleParams & S ){
    wxArrayString modes( nModes, kModes );
-   S.Optional( bHasFirstTrack).Define( mFirstTrack, wxT("First"), 0, 0, 100);
-   S.Optional( bHasLastTrack ).Define( mLastTrack,  wxT("Last"),  0, 0, 100);
-   S.DefineEnum( mMode, wxT("Mode"), 0, modes );
+   S.OptionalN( bHasFirstTrack).Define( mFirstTrack, wxT("First"), 0, 0, 100);
+   S.OptionalN( bHasLastTrack ).Define( mLastTrack,  wxT("Last"),  0, 0, 100);
+   S.OptionalY( bHasMode      ).DefineEnum( mMode,   wxT("Mode"), 0, modes );
    
    return true;
 }
@@ -141,6 +142,7 @@ void SelectTracksCommand::PopulateOrExchange(ShuttleGui & S)
    S.EndMultiColumn();
    S.StartMultiColumn(2, wxALIGN_CENTER);
    {
+      // Always used, so no check box.
       S.TieChoice( _("Mode:"), mMode, &modes);
    }
    S.EndMultiColumn();
diff --git a/src/commands/SelectCommand.h b/src/commands/SelectCommand.h
index 410e58f0d..457b67cfe 100644
--- a/src/commands/SelectCommand.h
+++ b/src/commands/SelectCommand.h
@@ -45,6 +45,7 @@ public:
 
    bool bHasT0;
    bool bHasT1;
+   bool bHasFromEnd;
 
    double mT0;
    double mT1;
@@ -86,6 +87,7 @@ public:
 
    bool bHasFirstTrack;
    bool bHasLastTrack;
+   bool bHasMode;
 
    int mFirstTrack;
    int mLastTrack;
diff --git a/src/commands/SetEnvelopeCommand.cpp b/src/commands/SetEnvelopeCommand.cpp
index 621fee83f..8dc649d40 100644
--- a/src/commands/SetEnvelopeCommand.cpp
+++ b/src/commands/SetEnvelopeCommand.cpp
@@ -31,12 +31,11 @@ SetEnvelopeCommand::SetEnvelopeCommand()
 
 
 bool SetEnvelopeCommand::DefineParams( ShuttleParams & S ){ 
-   S.Optional( bHasTrackIndex     ).Define(  mTrackIndex,     wxT("Track"),      0, 0, 100 );
-   S.Optional( bHasChannelIndex   ).Define(  mChannelIndex,   wxT("Channel"),    0, 0, 100 );
-   S.Optional( bHasContainsTime   ).Define(  mContainsTime,   wxT("At"),         0.0, 0.0, 100000.0 );
-   S.Optional( bHasT              ).Define(  mT,              wxT("Time"),     0.0, 0.0, 100000.0);
-   S.Optional( bHasV              ).Define(  mV,              wxT("Value"),    0.0, 0.0, 2.0);
-   S.Optional( bHasDelete         ).Define(  mbDelete,        wxT("Delete"),   false );
+   S.OptionalY( bHasTrackIndex     ).Define(  mTrackIndex,     wxT("Track"),      0, 0, 100 );
+   S.OptionalN( bHasChannelIndex   ).Define(  mChannelIndex,   wxT("Channel"),    0, 0, 100 );
+   S.OptionalY( bHasT              ).Define(  mT,              wxT("Time"),     0.0, 0.0, 100000.0);
+   S.OptionalY( bHasV              ).Define(  mV,              wxT("Value"),    0.0, 0.0, 2.0);
+   S.OptionalN( bHasDelete         ).Define(  mbDelete,        wxT("Delete"),   false );
    return true;
 };
 
@@ -48,7 +47,6 @@ void SetEnvelopeCommand::PopulateOrExchange(ShuttleGui & S)
    {
       S.Optional( bHasTrackIndex  ).TieNumericTextBox(  _("Track Index:"),   mTrackIndex );
       S.Optional( bHasChannelIndex).TieNumericTextBox(  _("Channel Index:"), mChannelIndex );
-      S.Optional( bHasContainsTime).TieNumericTextBox(  _("At:"),            mContainsTime );
       S.Optional( bHasT           ).TieNumericTextBox(  _("Time:"),          mT );
       S.Optional( bHasV           ).TieNumericTextBox(  _("Value:"),         mV );
       S.Optional( bHasDelete      ).TieCheckBox(        _("Delete:"),        mbDelete );
@@ -84,9 +82,9 @@ bool SetEnvelopeCommand::Apply(const CommandContext & context)
          for(auto it = ptrs.begin(); (it != ptrs.end()); it++ ){
             pClip = *it;
             bFound = 
-               !bHasContainsTime || (
-                  ( pClip->GetStartTime() <= mContainsTime ) &&
-                  ( pClip->GetEndTime() >= mContainsTime )
+               !bHasT || (
+                  ( pClip->GetStartTime() <= mT) &&
+                  ( pClip->GetEndTime() >= mT )
                );
             if( bFound )
             {
diff --git a/src/commands/SetEnvelopeCommand.h b/src/commands/SetEnvelopeCommand.h
index 635f59367..fb195576d 100644
--- a/src/commands/SetEnvelopeCommand.h
+++ b/src/commands/SetEnvelopeCommand.h
@@ -39,14 +39,12 @@ public:
 public:
    int mTrackIndex;
    int mChannelIndex;
-   double mContainsTime;
    double mT;
    double mV;
    bool mbDelete;
 
    bool bHasTrackIndex;
    bool bHasChannelIndex;
-   bool bHasContainsTime;
    bool bHasT;
    bool bHasV;
    bool bHasDelete;
diff --git a/src/commands/SetProjectCommand.cpp b/src/commands/SetProjectCommand.cpp
index 568288e74..ccf1bfcba 100644
--- a/src/commands/SetProjectCommand.cpp
+++ b/src/commands/SetProjectCommand.cpp
@@ -31,11 +31,11 @@ SetProjectCommand::SetProjectCommand()
 
 
 bool SetProjectCommand::DefineParams( ShuttleParams & S ){ 
-   S.Optional( bHasName        ).Define(     mName,        wxT("Name"),       _("Project") );
-   S.Optional( bHasSizing      ).Define(     mPosX,        wxT("X"),          10.0, 0.0, 2000.0);
-   S.Optional( bHasSizing      ).Define(     mPosY,        wxT("Y"),          10.0, 0.0, 2000.0);
-   S.Optional( bHasSizing      ).Define(     mWidth,       wxT("Width"),      1000.0, 200.0, 4000.0);
-   S.Optional( bHasSizing      ).Define(     mHeight,      wxT("Height"),      900.0, 200.0, 4000.0);
+   S.OptionalN( bHasName        ).Define(     mName,        wxT("Name"),       _("Project") );
+   S.OptionalY( bHasSizing      ).Define(     mPosX,        wxT("X"),          10.0, 0.0, 2000.0);
+   S.OptionalY( bHasSizing      ).Define(     mPosY,        wxT("Y"),          10.0, 0.0, 2000.0);
+   S.OptionalY( bHasSizing      ).Define(     mWidth,       wxT("Width"),      1000.0, 200.0, 4000.0);
+   S.OptionalY( bHasSizing      ).Define(     mHeight,      wxT("Height"),      900.0, 200.0, 4000.0);
    return true;
 };