I have tried to change my avatar this day and it don't work. results: I have no avatar now.
I used differents old-avatars and differents browsers (IE 6.0 and Mozilla 0.9.6). I have one message with Mozilla telling that it had been an upload error.
I have tried 30 time and I'm now too busy to do more searches.
Hoping you will be able to solve this,
your devoted, KissCool.