diff --git a/src/Project.cpp b/src/Project.cpp
index 06d23eaa0..eb22c63d9 100644
--- a/src/Project.cpp
+++ b/src/Project.cpp
@@ -737,6 +737,7 @@ AudacityProject::AudacityProject(wxWindow * parent, wxWindowID id,
      mMixerBoardFrame(NULL),
      mFreqWindow(NULL),
      mToolManager(NULL),
+     mbBusyImporting(false), 
      mAudioIOToken(-1),
      mIsDeleting(false),
      mTracksFitVerticallyZoomed(false),  //lda
@@ -1819,16 +1820,17 @@ void AudacityProject::OnMouseEvent(wxMouseEvent & event)
 //     and/or attempts to delete objects twice.
 void AudacityProject::OnCloseWindow(wxCloseEvent & event)
 {
+   if (event.CanVeto() && (::wxIsBusy() || mbBusyImporting)) 
+   {
+      event.Veto();
+      return;
+   }
+
    if (mFreqWindow) {
       mFreqWindow->Destroy();
       mFreqWindow = NULL;
    }
 
-   if (wxIsBusy()) {
-      event.Veto();
-      return;
-   }
-
    // Check to see if we were playing or recording
    // audio, and if so, make sure Audio I/O is completely finished.
    // The main point of this is to properly push the state
diff --git a/src/Project.h b/src/Project.h
index 9cc6dbe2c..eb84f3400 100644
--- a/src/Project.h
+++ b/src/Project.h
@@ -492,6 +492,7 @@ class AUDACITY_DLL_API AudacityProject:  public wxFrame,
    bool mShowSplashScreen;
    wxString mHelpPref;
    wxString mSoloPref;
+   bool mbBusyImporting; // used to fix bug 584
 
    void SetNormalizedWindowState(wxRect pSizeAndLocation) {  mNormalizedWindowState = pSizeAndLocation;   }
    wxRect GetNormalizedWindowState() const { return mNormalizedWindowState;   }
diff --git a/src/import/Import.cpp b/src/import/Import.cpp
index ec65354a0..c64a5521b 100644
--- a/src/import/Import.cpp
+++ b/src/import/Import.cpp
@@ -327,6 +327,9 @@ int Importer::Import(wxString fName,
                      Tags *tags,
                      wxString &errorMessage)
 {
+   AudacityProject *pProj = GetActiveProject();
+   pProj->mbBusyImporting = true;
+
    ImportFileHandle *inFile = NULL;
    int numTracks = 0;
 
@@ -670,6 +673,8 @@ int Importer::Import(wxString fName,
       errorMessage.Printf(_("Audacity recognized the type of the file '%s'.\nImporters supposedly supporting such files are:\n%s,\nbut none of them understood this file format."),fName.c_str(), pluglist.c_str());
    }
 
+   pProj->mbBusyImporting = false;
+
    return 0;
 }