Bug 93245 [Dialogs] Error messages show up in two locations in the properties dialog
Force an error message: 1) select a Java project 2) open the properties dialog 3) navigate to Java Compiler>Building 4) enable project specific settings 5) enter a letter into the maximum number of problems field ->the error message shows up at the bottom 6) resize the dialog ->the error message also shows up in the banner
bundles/org.eclipse.jface/src/org/eclipse/jface/preference/PreferenceDialog.java
/**
	 * Shows the preference page corresponding to the given preference node.
	 * Does nothing if that page is already current.
	 * 
	 * @param node
	 *            the preference node, or <code>null</code> if none
	 * @return <code>true</code> if the page flip was successful, and
	 *         <code>false</code> is unsuccessful
	 */
	protected boolean showPage(IPreferenceNode node) {
		if (node == null)
			return false;
		
		if (node.getPage() == null)
			createPage(node);
		if (node.getPage() == null)
			return false;
		IPreferencePage newPage = getPage(node);
		if (newPage == currentPage)
			return true;
		if (currentPage != null) {
			if (!currentPage.okToLeave())
				return false;
		}
		IPreferencePage oldPage = currentPage;
		currentPage = newPage;
		
		currentPage.setContainer(this);