[Dovecot] Corrupted transaction log file, dotlocks..?

[John and Catherine Allen]

I'm new to Dovecot but I've been able to get it up and running on a test 
basis without too much difficulty. I'm running dovecot-stable-20050508 
with maildir, under Linux (an old Gentoo setup that's been stable for 
about 2,5 years). Mail client is Thunderbird.

However, in the course of experimentally copying the accumulated 
household email (95000 emails from the last 10 years) from the existing 
IMAP server (UW-IMAP) using imapsync, I'm seeing some problems.

While copying the 1000 or so messages from the main INBOX, Dovecot seems 
to hang after 50-100 messages and the following lines appear in the 
server log:

May 15 18:45:21 [dovecot] IMAP(allen): 
utime(/home/allen/Maildir/dovecot-uidlist.lock) failed: No such file or 
directory
May 15 18:45:21 [dovecot] IMAP(allen): Our dotlock file 
/home/allen/Maildir/dovecot-uidlist.lock was deleted
May 15 18:45:21 [dovecot] IMAP(allen): Corrupted transaction log file 
/home/allen/Maildir/dovecot.index.log: Append with UID 1827, but 
next_uid = 1828
May 15 18:45:21 [dovecot] IMAP(allen): Lost transaction log file 
/home/allen/Maildir/dovecot.index.log seq 4
May 15 18:45:21 [dovecot] IMAP(allen): Lost transaction log file 
/home/allen/Maildir/dovecot.index.log seq 4
May 15 18:45:21 [dovecot] IMAP(allen): Corrupted transaction log file 
/home/allen/Maildir/dovecot.index.log: Append with UID 1827, but 
next_uid = 1828
May 15 18:45:21 [dovecot] IMAP(allen): Lost transaction log file 
/home/allen/Maildir/dovecot.index.log seq 4
[...20 identical lines deleted....]
May 15 18:48:27 [dovecot] imap-login: Login: allen [192.168.0.1]
May 15 18:48:57 [dovecot] imap-login: Login: allen [192.168.0.1]
May 15 18:48:57 [dovecot] IMAP(allen): Transaction log file 
/home/allen/Maildir/dovecot.index.log: marked corrupted

I can restart after deleting the dovecot files in ~/Maildir, but the 
problem recurs.

In other folders I've been able to copy large numbers of emails 
successfully with imapsync. I've not experienced any problems while 
accessing the folders with Thunderbird.

I can't relate these log messages to anything in the configuration file 
or the documentation, so I'm wondering if I can ask for help?

John

-- 
John Allen
Bofferdange, Luxembourg
allen at vo.lu
http://www.homepages.lu/allen