Hmmmmm, well, my first suggestion would be to make sure it's sized correctly. Secondly, make sure you are trying to change your "avatar" picture and not your "profile" picture (oddly enough, they are 2 different things).
If you are still having problems, if you want to send me your photo, I can put it up for you from the back end.
Just load it somewhere like photobucket and PM me the link.
I hope that helps! Please let us know if you have any other questions!