Do you get an error message?
Can you upload/try any other images as avatar?
If the file maybe too big or not an allowed extension?
You can try in localhost if you want, it's not working really, i have a cotonti site but any members can't select from gallery to avatar !
Added 1 days later:
Why anybody not fixing ? this bug about :S
Kurta sormuşlar senin ensen neden kalın ? diye, Kendi işimi kendim yaparımda ondan demiş...