Bug 110087 [Markers] "Filters" menu doesn't remember the last selected filter
When I was playing with this it was a true pain. I'd change somes ettings to see what effect it had and then re-open the dialog to try some other settings I had to re-select my filter (it selects the first one always)...
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/internal/provisional/views/markers/FiltersConfigurationDialog.java
parent.getShell().setText(
				NLS.bind(MarkerMessages.filtersDialog_title_content,
						contentGenerator.getName()));
		Composite top = (Composite) super.createDialogArea(parent);
		initializeDialogUnits(top);
		GridLayout layout = new GridLayout();
		layout.numColumns = 2;
		layout.makeColumnsEqualWidth = false;
		top.setLayout(layout);
		createFilterSelectionArea(top);
		final FormToolkit toolkit = new FormToolkit(top.getDisplay());
		parent.addDisposeListener(new DisposeListener() {
			public void widgetDisposed(DisposeEvent e) {
				toolkit.dispose();
			}
		});
		form = toolkit.createScrolledForm(top);
		form.setBackground(parent.getBackground());
		GridData data = new GridData(SWT.FILL, SWT.FILL, true, true);
		form.setLayoutData(data);
		form.getBody().setLayout(new GridLayout());
		filterAreas = contentGenerator.createFilterConfigurationFields();
		
		createFieldArea(toolkit, form, scopeArea,true);
		Iterator areas = filterAreas.iterator();
		
		
		while (areas.hasNext()) {
			createFieldArea(toolkit, form, (FilterConfigurationArea) areas
					.next(), true);