Bug 131484 Can't not add item by click the item from palette
Details: Can't not add item Setp: 1.New a report design and open the palette. 2.Click the lable icon. 3.Move the mouse to layout and click again to add the label. Actual result: Nothing is added in layout.
UI/org.eclipse.birt.report.designer.ui.ide/src/org/eclipse/birt/report/designer/ui/editors/ReportEditorProxy.java
{
		if ( instance != null )
		{
			getSite( ).getWorkbenchWindow( )
					.getPartService( )
					.removePartListener( instance );
			instance.dispose( );
		}
		if ( input instanceof IFileEditorInput )
		{
			instance = new IDEMultiPageReportEditor( );
		}
		else
		{
			instance = new MultiPageReportEditor( );
		}
		instance.init( site, input );
		instance.addPropertyListener( this );
		getSite( ).getWorkbenchWindow( )
				.getPartService( )
				.addPartListener( this );
		setPartName( getEditorInput( ).getName( ) );
	}
	public void createPartControl( Composite parent )
	{
		instance.createPartControl( parent );
	}
	public void dispose( )
	{
		if ( instance != null )