[Dovecot] mail-cache-transaction.c error

[F. Even]

Hello all.  I've just recently (this last weekend) migrated to Dovecot 
on my FreeBSD 4.x box.  So far, so good, I like it a lot, and plan on 
moving mboxes to Maildirs sometime this next weekend.

BUT....I've currently run into a problem.  I'm seeing an error when 
one user account tries to access the INBOX from Squirrelmail:

Mar  6 16:50:59 cerebus dovecot: IMAP(problemuser): file mail-cache-
transaction.c: line 250 (mail_cache_transaction_reserve_more): 
assertion failed: (size >= 2)

I'm using 1.0-test63:

Mar  6 04:17:47 cerebus dovecot: Dovecot v1.0-test63 starting up

I've since blown away the .imap folder for this user and tried again, 
it still fails.  Other user accounts are having no problems.  Here are 
the relevant log snippets:

Mar  6 16:18:02 cerebus dovecot: imap-login: Login: noproblems 
[127.0.0.1]
Mar  6 16:48:48 cerebus dovecot: imap-login: Login: problemuser 
[127.0.0.1]
Mar  6 16:48:49 cerebus dovecot: imap-login: Login: problemuser 
[127.0.0.1]
Mar  6 16:48:52 cerebus dovecot: IMAP(problemuser): file mail-cache-
transaction.c: line 250 (mail_cache_transaction_reserve_more): 
assertion failed: (size >= 2)
Mar  6 16:48:52 cerebus dovecot: child 64331 (imap) killed with signal 
6
Mar  6 16:48:52 cerebus dovecot: imap-login: Login: problemuser 
[127.0.0.1]
Mar  6 16:50:42 cerebus dovecot: imap-login: Login: problemuser 
[127.0.0.1]
Mar  6 16:50:59 cerebus dovecot: IMAP(problemuser): file mail-cache-
transaction.c: line 250 (mail_cache_transaction_reserve_more): 
assertion failed: (size >= 2)
Mar  6 16:50:59 cerebus dovecot: child 64391 (imap) killed with signal 
6
Mar  6 16:52:54 cerebus dovecot: imap-login: Login: problemuser 
[127.0.0.1]
Mar  6 16:52:57 cerebus last message repeated 2 times
Mar  6 16:52:58 cerebus dovecot: IMAP(problemuser): file mail-cache-
transaction.c: line 250 (mail_cache_transaction_reserve_more): 
assertion failed: (size >= 2)
Mar  6 16:52:58 cerebus dovecot: child 64420 (imap) killed with signal 
6
Mar  6 16:53:31 cerebus dovecot: imap-login: Login: noprob2 [127.0.0.1]
Mar  6 16:53:54 cerebus last message repeated 4 times
Mar  6 16:56:12 cerebus last message repeated 12 times
Mar  6 16:58:12 cerebus last message repeated 11 times
Mar  6 16:58:30 cerebus dovecot: imap-login: Login: noproblems 
[127.0.0.1]
Mar  6 16:58:34 cerebus last message repeated 2 times

Any help would be appreciated.

Thanks,
Frank