I bet you are right Ruben.
Sherri should check the CP > Group Management > (admins) Forum Permissions > and check/change settings for both 'Delete post time limit' and 'Edit post time limit' and enter large enough numbers (to get back to the date of the spam posts). I'd also look at 'Delete Topics' and 'Edit any post' to ensure they are set to 1 (not 0).
Banning the members with 'delete all posts' option ticked is quick, yet you want the edit and delete forums permissions set up properly to suit your board, regardless.
