Bug 146159 [Regression]Changing font operation doesn't work other than the first time
Description: The first time changing operation can work well. However, Change it again, it won't work. Steps: 1.Insert lable/text to layout or master page 2.Change the font from serif to cursive, it works well 3.Change the font again Result: The action doesn't work Additional infor: build number:200606080632
UI/org.eclipse.birt.report.designer.ui/src/org/eclipse/birt/report/designer/ui/dialogs/HighlightRuleBuilder.java
gdata.widthHint = 50;
		backColor.setLayoutData( gdata );
		backColor.setChoiceSet( ChoiceSetFactory.getElementChoiceSet( ReportDesignConstants.STYLE_ELEMENT,
				StyleHandle.BACKGROUND_COLOR_PROP ) );
		backColor.setRGB( null );
		backColor.addListener( SWT.Modify, new Listener( ) {
			public void handleEvent( Event event )
			{
				previewLabel.setBackground( ColorManager.getColor( backColor.getRGB( ) ) );
				previewLabel.redraw( );
			}
		} );
		Composite preview = new Composite( innerParent, SWT.NONE );
		glayout = new GridLayout( );
		preview.setLayout( glayout );
		gdata = new GridData( GridData.FILL_BOTH );
		preview.setLayoutData( gdata );
		lb = new Label( preview, SWT.NONE );
		lb.setText( Messages.getString( "HighlightRuleBuilderDialog.text.Preview" ) ); 
		Composite previewPane = new Composite( preview, SWT.BORDER );
		glayout = new GridLayout( );
		glayout.marginWidth = 0;
		glayout.marginHeight = 0;
		previewPane.setLayout( glayout );
		gdata = new GridData( GridData.FILL_BOTH );
		gdata.heightHint = 60;
		previewPane.setLayoutData( gdata );
		previewLabel = new PreviewLabel( previewPane, 0 );
		previewLabel.setText( Messages.getString( "HighlightRuleBuilderDialog.text.PreviewContent" ) ); 
		gdata = new GridData( GridData.FILL_BOTH );