[otrs] Escalation on Pending Auto Close+

Hi list! I have tickets that escalate although they are in auto close + state - this is not what I expected. I've googled and found other references (http://www.mail-archive.com/otrs@otrs.org/msg30658.html) but no solution was come up there either. Could it be that tickets are escalated when they don't have a state of type "closed"? If so, should I change the state of the pending auto close to "closed"? What unwanted results could that have? Thanks, Arthur