awww thanks Matt. I can do that..never thought of it. It is a small plastic piece that levels the HOB. Mine is now not level but seems to be working fine. I will do more reseach, and will post here for others.
I think I know what you are talking about now. It is that little thing on the bottom outside of the filter that sits against the glass to keep the filter level. If that is the case I would try to put something there to keep the filter level or even slightly leaning forward. It shouldn't hurt the filter but if the filter is leaning back you may wake up to water outside the tank. If the filter overflows for any reason, instead of the water going in the tank through the over flow it could start overflowing onto your floor.
I've lost this plenty of times it'll work fine til you get a new one.