I signed up for talkbass recently, but on my UserCP I can't add an avatar, there is only one box labelled, "Do not use an avatar" that can only be checked. Wondering how I can solve this problem and add an avatar to my profile ?

thanks

http://www.talkbass.com/content/support.php?styleid=11

The only way to get an avatar is to become a supporting member. That link will tell you all about it.