You can't edit your forum profile information, e.g. add an avatar, etc. until you have 20 posts.
The problem comes from drive by spammers, who having registered put objectionable or commercial links in their profile signature to try and gain link promotion, etc.
There have also been cases of the PM function being abused to spam forum members, so you will notice that you can't use the PM function either.
Unfortunately because of the actions of others legitimate members suffer by the actions to prevent this spamming.
