User disappeard from back, but can still log in

[kipprsnak1]

I have a subscriber who has disappeared from my Users admin list, but can still login on the front end.

Has anyone seen this behavior? I remember a post about something similar, but I can't find that post now. Any ideas?

Thanks!

[kipprsnak1]

In order to try to deal with my member's issue, I re-imported the user. Now she appears in the back end (why did she leave in the first place??) but now I'm getting this error:
Warning: date() expects parameter 2 to be long, string given in /wp-content/plugins/s2member/includes/functions/users-list.inc.php on line 79

I exported a list from S2Member and then imported using that list, so not sure if there was something in the reg date that was wrong or???

Thanks for any help!