Bug 81292 [Preferences] Message area should be disabled when empty
200412152000 My GTK theme has a textured background by default. There is a section of the preference dialog next to the Default/Apply buttons that does not respect this. I suspect there is an empty label/text widget that has had its background colour set manually. Screencap forthcoming
bundles/org.eclipse.jface/src/org/eclipse/jface/preference/PreferencePage.java
* @param title the title of this preference page
     */
    protected PreferencePage(String title) {
        super(title);
    }
    /**
     * Creates a new abstract preference page with the given title and image.
     *
     * @param title the title of this preference page
     * @param image the image for this preference page,
     *  or <code>null</code> if none
     */
    protected PreferencePage(String title, ImageDescriptor image) {
        super(title, image);
    }
    /**
     * Computes the size for this page's UI control.
     * <p>
     * The default implementation of this <code>IPreferencePage</code>
     * method returns the size set by <code>setSize</code>; if no size
     * has been set, but the page has a UI control, the framework
     * method <code>doComputeSize</code> is called to compute the size.
     * </p>
     *
     * @return the size of the preference page encoded as
     *   <code>new Point(width,height)</code>, or 
     *   <code>(0,0)</code> if the page doesn't currently have any UI component
     */
    public Point computeSize() {
        if (size != null)