customized registration: users can't receive PMs
 

Hello,

On my site all members are registered to VBulletin when they sign up on the site's reg form. This is done by inserting their personal values in vb_user and vb_userfield. It works very well except for one thing: users created this way can't receive private messages, when I try to send a private message to them I get a Database error (The Forum database has encountered a problem...), the private message then appears in the senders outbox but not in the recipient's inbox.

I find this problem very strange and don't really see a clue... The values in vb_user and vb_userfield are all the same in regular and in customized registration, what can I have missed?