[Dovecot] Corrupted index cache file

Anyone have a hint as to how I might successfully debug this problem?

Dec 6 11:19:38 aurora dovecot: IMAP(doug): Corrupted index cache file /home/doug/Maildir/dovecot.index.cache: record list is circular

Dec 6 11:20:02 aurora dovecot: IMAP(doug): msync() failed with index file /home/doug/Maildir/dovecot.index: Invalid argument

(w/test56)

Thanks,

Doug