Since I know diddlysquat about PHP/CGI and hacking Jelsoft's vBulletin Board, take this merely for an example's perspective.

Apparently you can enter in HTML for the users' custom title.
I have been successful at "assigning" a flash custom title to a user and turning off his/her avatar. I know this is a roundabout way of doing things, but it might be a start for some of you.

To clarify a bit more on the issue, I would really like a user to be able to upload his/her flash avatar and use it immediately.

I don't personally care if there is a width/height requirement, just so long as a user can create the avatar his/herself. I also don't care whether or not this avatar will be seen in the list of avatars (i have the avatar category hack installed), but it would be nice.

Thanks.

I can help trouble shoot in anway possible, but we need a starting point.