So I have a user that I can't activate with the unconfirmed plugin manually. His user was created on all appropriate sites, but his account isn't listed as activated. The link in the activation email just returns the error message: "Could not create user" even though he was created. The Unconfirmed module simply tells me "The following users could not be activated: ".*.
I looked in his user table and the key in the email matches what's in the DB, the only thing in the signups table that was odd was that he didn't have an activation time.
Any ideas on what's going on and how I can fix it?
*Edit: There's also nothing in my apache logs indicating a php error.