CLR48, You said that your stand was perfectley level when you built it that you checked. I assume that was after you skinned and finished it. I wouldn't think that the stand is "Racked" or out of square at this point. You could check the floor or table it was built on to see if there level. Your picture shows it sitting on a wood floor. I would check to see if the floor is level. If it's not level than there's your problem. Shimming the stand to make it level is fine, but my bigger concern is if the floor is un-level what caused it and is it safe for that much weight ?