I've never really played with the registration process, but looking at the code, I'm wondering if you are picking a hook location that is after the userdata save process. Have you tried using the hook "register_addmember_process"? It looks like the save occurs after that one but before the one you picked. In fact, look at line 359, that is where the usergroupid is set. You may just need to just make a userdate->set call like that one at the hook location I suggested.
|