[Dovecot] UID related error message

I'm not sure exactly what it means, but it repeats over and over again for 2 different boxes on my system:

Error: IMAP(trisha): Corrupted transaction log file /var/spool/mailindex/trisha/SPAM/dovecot.index.log: Append with UID 58332, but next_uid = 59582 Error: IMAP(trisha): Transaction log file /var/spool/mailindex/trisha/SPAM/dovecot.index.log: marked corrupted

It seems to repeatedly mark it corrupted but then never does anything about it?

Client is outlook express, and only dovecot 0.99.10 and 1.0-test45 have ever been used to access this mbox.

• Mike