ScanForNewMail Blackberry Error

Why is that half the errors I get on my servers have never been seen by anyone else??

Getting an event id 20091 on the Blackberry server with the error: The following information is part of the event: Exception in ScanForNewMail for user {user}

The user is not getting any emails at the moment, but was previously getting the same single message over and over again. We deleted that email out of her mail file and they stopped coming, but nothing else has come through since it had started happening.

Will try recreating her setup on the Blackberry server, see if that fixes it. Presumably something is corrupt in her setup somewhere....