Register Plus: username missing

I’m experiencing a very strange problem with WordPress 3.0.1 using Register Plus. *Sporadically,* usernames will come through blank after they are verified, and the user cannot log in.

A username shows up in the administrator approval message, but it’s not there when I look at the admin page. Here’s an image of the user admin screen:

http://img708.imageshack.us/img708/8656/missingusers.png

I found this old thread: http://wordpress.org/support/topic/new-registration-username-is-blank

but the users aren’t using spaces for usernames, as they appear in the registration email. I also found another thread stating that you cannot have email verification checked in conjunction with admin approval, but I have that box unchecked already.

Is anyone else experiencing this problem? Again, it only occurs once in a while, and I can’t find any rhyme or reason as to why.

Thanks very much.