Bug#358742: cyrus21-imapd process hangs on sent mailbox

[Matt Boes]

Package: cyrus21-imapd
Version: 2.1.18-1

Approximately once per month, one cyrus-imapd process hangs when a user 
tries to store a sent message in his sent mailbox.  This user is using 
Thunderbird 1.0.7 as his mail client.
This message appears in the log:

Mar 23 21:29:30 localhost cyrus/imapd[32537]: IOERROR: locking header 
for user.jl-jennings.Sent: Interrupted system call

The user then cannot access this sent mail folder until this process is 
manually killed.

Another example of this bug with the same package and the same mail 
client is here:
http://archives.free.net.ph/message/20051203.113734.9e6eca98.en.html

This also seems to be unresolved.

This seems to happen somewhat randomly, as I cannot reproduce it for any 
other account other than this user's, and it happens to this user 
sometimes twice in a week, sometimes not for two months.

The mail server is running Debian GNU/Linux 3.1, kernel 2.4.29, and 
libc6 2.3.2.ds1-22.
Cyrus is running on ports 143 and 993 over SSL with saslauthd, libsasl2 
version 2.1.19-1.5.