I think I bent something
 

I have a 503 head with the 755B legs. I took the 503 off and had it on a monopod awhile and when I put it back on the 755B now the level does not stay level for very long. That is if I level the head with the self-leveler, the head goes about fifty degrees before the bubble dives right forward and does not level again until another two hundred degrees. Meanwhile the bubble on the legs stays constant. The tilt is at it's worst at 180 degrees.

Did I bend something? If so, is there a fix?

I have taken the head off and put it back on several times with the same result. I've also tried different rooms.

On line questionnaire why question wasn't answered.

A. Question was too boring and obvious.
B. Not enough information in question.
C. No mention of Anna Nicole Smith anywhere in question.
D. The answer is 42.
E. All of the above.

B. It's too hard to guess what may be the issue.

A picture would help, you can attach one to a post.

Thanks Nate, in the process of taking photos I discovered the problem was a bent connector thread.