I wouldn't know about that I didn't try to put my avatar on till quite late and I may have been a regular by then, not sure, if you look at some other posts and the replies you will find one's that says moderator click on there name and it should open up another page and you can pm them privately and ask why you can't put it on and they maybe able to help you.
they should also see your post as they do check posts and they may reply to you. good luck