Bug 189393 Can not drop the item into cross table row
Description: Can not drop the item into cross table row Step: 1. New a cross table. 2. Drop any item from palette into cross table row. Actual result: The item cannot drop in it.
UI/org.eclipse.birt.report.designer.ui/src/org/eclipse/birt/report/designer/internal/ui/editors/schematic/tools/ReportCreationTool.java
SessionHandleAdapter.getInstance( )
					.getReportDesignHandle( )
					.getCommandStack( )
					.rollback( );
			handleFinished( );
			return;
		}
		SessionHandleAdapter.getInstance( )
				.getReportDesignHandle( )
				.getCommandStack( )
				.commit( );
		selectAddedObject( );
		isCreating = false;
	}
	/**
	 * Performs the creation. Runs the creation via simulating the mouse move
	 * event.
	 * 
	 * @param editPart
	 *            the current EditPart
	 */
	public void performCreation( EditPart editPart )
	{
		if ( editPart == null )
			return;
		setTargetEditPart( editPart );
		boolean validateCurr = handleValidatePalette( getFactory( ).getObjectType( ),
				getTargetEditPart( ) );
		if ( !validateCurr )
		{