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.core/src/org/eclipse/birt/report/designer/util/DEUtil.java
{
			Font defaultFont = JFaceResources.getDefaultFont( );
			FontData[] fontData = defaultFont.getFontData( );
			fontSize = fontData[0].getHeight( );
		}
		if ( DesignChoiceConstants.UNITS_EM.equals( units ) )
		{
			px = DimensionUtil.convertTo( measure * fontSize,
					DesignChoiceConstants.UNITS_PT,
					DesignChoiceConstants.UNITS_IN ).getMeasure( );
		}
		else if ( DesignChoiceConstants.UNITS_EX.equals( units ) )
		{
			px = DimensionUtil.convertTo( measure * fontSize / 3,
					DesignChoiceConstants.UNITS_PT,
					DesignChoiceConstants.UNITS_IN ).getMeasure( );
		}
		else if ( DesignChoiceConstants.UNITS_PERCENTAGE.equals( units ) )
		{
			px = DimensionUtil.convertTo( measure * fontSize / 100,
					DesignChoiceConstants.UNITS_PT,
					DesignChoiceConstants.UNITS_IN ).getMeasure( );
		}
		
		else if ( "".equals( units ) ) 
		{
			units = SessionHandleAdapter.getInstance( ).getReportDesignHandle( )
					.getDefaultUnits( );
			px = DimensionUtil.convertTo( measure, units,
					DesignChoiceConstants.UNITS_IN ).getMeasure( );