Hmmmmm...not sure. Have you been fitted by a professional yet (and I don't mean just the stand-over check and other silly "fittings" some bike shops give)?
My LBS does a thorough bike fitting (charges $40- but it's well worth it to get the correct fit). He measures everything and then puts the #'s into his computer, gets some great printout and then adjusts the bike as needed. Very thorough and very worth it.
I would suggest getting a thorough fitting first to see what the problem is.

If you've already been fitted, then I would suggest taking pictures of you on your bike at different angles to see if something looks wrong, and then adjust as needed.