The biggest problem, by far, with getting avatars to work is that people sign up to Gravatar with the wrong email address. You MUST use the SAME address as you've got registered with the Answerbank. If You've forgotten what that is, click 'My Profile' and then 'Edit My Profile' to view it.
If you go into AB My profile and then into Edit Profile is the avatar showing?
Have you ticked the check box on your profile to activate it?
Sometimes it takes 15 minutes to come through from Gravatar to AB.
Cookies aren't the cause of the problem, Usathome.
Sometimes a user will find that their old avatar (or the default avatar if they're just creating their first personal one) will still show on their own screen until they clear their browser's cache. (NB: It's the cache that needs to be cleared, not cookies). However everyone else will see the new avatar.
The fact that nobody can yet see Bobbie's avatar means that the problem is elsewhere.