Failing to creating the dialog switcher

gistfile1.cpp

#include "VCPlugInHeaders.h"

// Interface includes:
#include "ISession.h"
#include "IApplication.h"
#include "IDialogMgr.h"
#include "IDialog.h"

#include "IDialogCreator.h"
#include "IK2ServiceProvider.h"
#include "IK2ServiceRegistry.h"
#include "IPanelControlData.h"
#include "ISelectableDialogSwitcher.h"

// General includes:
#include "CActionComponent.h"
#include "CAlert.h"

// Project includes:
#include "MGMImporterID.h"

// [...]

 void MGMImporterActionComponent::DoBasicSelectableDialog()
 {   
     do
     {  
         InterfacePtr<IK2ServiceRegistry> sRegistry(GetExecutionContextSession(), UseDefaultIID());
         if (sRegistry == nil)
             break;
         
         InterfacePtr<IK2ServiceProvider> 
            sdService(sRegistry->QueryServiceProviderByClassID(kSelectableDialogServiceImpl, kMGMDlgDialogBoss));
         
         if (sdService == nil)
             break;
         
         InterfacePtr<IDialogCreator> dialogCreator(sdService, IID_IDIALOGCREATOR);
         if (dialogCreator == nil)
             break;
         
         IDialog* dialog = dialogCreator->CreateDialog();
         if (dialog == nil)
             break;
         
         InterfacePtr<IPanelControlData> panelData(dialog, UseDefaultIID());
         if (panelData == nil)
             break;
         
         WidgetID    widgetID= kMGMImporterDialogWidgetID;
         IControlView* dialogView = panelData->FindWidget(widgetID);
         if (dialogView == nil)
             break;
         
         InterfacePtr<ISelectableDialogSwitcher> 
         dialogSwitcher(dialogView, IID_ISELECTABLEDIALOGSWITCHER);
         if (dialogSwitcher == nil)
         {
             // FAILING HERE !!
             ASSERT_FAIL("MGMImporterActionComponent::DoBasicSelectableDialog: dialogSwitcher invalid");
             break;
         }
         
         dialogSwitcher->SetDialogServiceID(kMGMDlgService);
         dialog->Open(); 
         
     }while(false);
 }