Cannot delete Voicemail message

I am having an issue with 1 user on 1 customer wherein she will seemingly randomly get a voicemail in her inbox that she is unable to delete. Upon examination, the voicemail is named in such a way as to be equal to the maxmsg setting. Unfortunately, since the naming convention starts at 0000, this is higher than what asterisk seems to be able to recognize. For instance, my maxmsg setting is 200. So starting at zero, the highest named message should be msg0199. However, she gets msg0200, which is actually message 201.

Now, in no way does she ever have 200 messages sitting in her INBOX at one time. I am confused as to how this message is getting named like this, and why asterisk is unable to remove it. Setting the maxmsg higher or lower has no effect, as the message will just be named to the the same value as the maxmsg limit, which is always one above the appropriate max.

We are currently running asterisk 1.4.18.1 on RHEL5.

Any thoughts ? Has anyone heard of this before ? It is only happening to her once a month or so, but is irritating for ALL of us because of the capitals she uses in her email about it !

Thanks in advance for any input !