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/internal/ui/dialogs/FontPreferencePage.java
public Object getModel() {
		return model;
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.jface.preference.FieldEditorPreferencePage#createFieldEditors()
	 */
	protected void createFieldEditors() {
		super.createFieldEditors();
		name = new EditableComboFieldEditor(StyleHandle.FONT_FAMILY_PROP,
				Messages.getString(((StyleHandle) model).getPropertyHandle(
						StyleHandle.FONT_FAMILY_PROP).getDefn()
						.getDisplayNameID()), getFontChoiceArray(),
				getFieldEditorParent());
		color = new ColorFieldEditor(StyleHandle.COLOR_PROP, Messages
				.getString(((StyleHandle) model).getPropertyHandle(
						StyleHandle.COLOR_PROP).getDefn().getDisplayNameID()),
				getFieldEditorParent());
		size = new ComboBoxMeasureFieldEditor(StyleHandle.FONT_SIZE_PROP,
				Messages.getString(((StyleHandle) model).getPropertyHandle(
						StyleHandle.FONT_SIZE_PROP).getDefn()
						.getDisplayNameID()),
				getChoiceArray(DesignChoiceConstants.CHOICE_FONT_SIZE),
				getChoiceArray(DesignChoiceConstants.CHOICE_UNITS),
				getFieldEditorParent());
		size.setDefaultUnit(((StyleHandle) model).getPropertyHandle(
				StyleHandle.FONT_SIZE_PROP).getDefaultUnit());
		style = new ComboBoxFieldEditor(StyleHandle.FONT_STYLE_PROP, Messages
				.getString(((StyleHandle) model).getPropertyHandle(