Hmmm, well I'm a bit confused because if I go to the member page for user 1 here:
http://www.empyron.com/forums/member.php?u=1 I can see no user profile picture showing up anywhere which is why I asked if guests can see them.
Did you start this forum from scratch or import a 'used' database? I ask cuz I recently lost a harddrive on another site and had to start from scratch with it - install php, mysql, etc - except I did have a backup database. I basically reinstalled vbulletin and then imported the old database (same version of vb) and I had a similar issue with the avatars. I had to rebuild the bitfields (I think that's what it was that 'fixed' it).