[Dovecot] 1.0rc3 problem w/ Thunderbird 1.5.0.5 on Mac OS X

[Herr Nagengast]

Howdy,

I'm very excited about the new dovecot release because I've been having
problems with a hang on saving messages to my sent-mail box over imap+ssl.

I installed 1.0rc3 over my 1.0rc2 install on FreeBSD 5.3 in the same
manner as all the other upgrades I've done. After checking my email,
tbird became nonresponsive and I saw this repeating in my logs ad infinitum:

Aug  2 10:17:10 grin dovecot: imap-login: Login: user=<todd>,
method=plain, rip=192.168.1.125, lip=64.142.74.74, TLS
Aug  2 10:17:10 grin dovecot: IMAP(todd): Effective uid=1001, gid=1001
Aug  2 10:17:10 grin dovecot: IMAP(todd): mbox:
data=/home/todd/mail:INBOX=/var/mail/todd
Aug  2 10:17:10 grin dovecot: IMAP(todd): mbox: root=/home/todd/mail,
index=/home/todd/mail, inbox=/var/mail/todd
Aug  2 10:17:10 grin dovecot: IMAP(todd): file index-mail.c: line 785:
unreached
Aug  2 10:17:10 grin dovecot: child 87476 (imap) killed with signal 6
Aug  2 10:17:10 grin dovecot: IMAP(todd): Effective uid=1001, gid=1001
Aug  2 10:17:10 grin dovecot: IMAP(todd): mbox:
data=/home/todd/mail:INBOX=/var/mail/todd
Aug  2 10:17:10 grin dovecot: IMAP(todd): mbox: root=/home/todd/mail,
index=/home/todd/mail, inbox=/var/mail/todd
Aug  2 10:17:10 grin dovecot: imap-login: Login: user=<todd>,
method=plain, rip=192.168.1.125, lip=64.142.74.74, TLS
Aug  2 10:17:11 grin dovecot: IMAP(todd): file index-mail.c: line 785:
unreached
Aug  2 10:17:11 grin dovecot: child 87478 (imap) killed with signal 6

Restarting my mail client had no effect on the problem, nor did
restarting the server.

For now, I've downgraded to 1.0rc2 and I'm not having any problems.

Thanks for any help!
Todd