There are also tons of other ways you can taint the objective tracker that don't even require touching the objective tracker itself. Personally I just gave up trying to get working quest item buttons on the objective tracker, and am using p3lim's
ExtraQuestButton addon to (basically) put quest items on the extra action button; it doesn't let you pick which item to use, but automatically selects the item based on your current location, and so far I've never needed to use a different item. Another option would be to use the quest item ring in
OPie, or another addon that creates a separate menu/bar for quest items.