Oh, right, I see now where you said you tried exactly that.
OK, right below where you inserted you code is this code:
Code:
if ($userid)
{
$userinfo = fetch_userinfo($userid,0,0,0,true); // Read Master
Try checking $userinfo['field5'], somewhere after that code.
The strange thing is that I can't see how $bbuserinfo would reflect the new value for field5 even in the vb3 code.