Bug 127289 [Markers] SystemFilter and group selection state not preserved
We are not preserving the selection state of the system filters or which group is selected.
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/views/markers/internal/CategorySorter.java
return innerSorter.compare(marker1, marker2, depth,
					continueSearching);
		}
		int result = categoryField.compare(marker1, marker2);
		if (continueSearching && result == 0) {
			return innerSorter.compare(marker1, marker2, 0, continueSearching);
		}
		return result;
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.jface.viewers.ViewerSorter#compare(org.eclipse.jface.viewers.Viewer,
	 *      java.lang.Object, java.lang.Object)
	 */
	public int compare(Viewer viewer, Object e1, Object e2) {
		return compare(e1, e2, 0, true);
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see java.util.Comparator#compare(java.lang.Object, java.lang.Object)
	 */
	public int compare(Object arg0, Object arg1) {
		return compare(arg0, arg1, 0, true);
	}
	/**
	 * Get the category field.
	 * 
	 * @return IField