[Dovecot] Multiple instances of .customflags staying open

[Ron]

# cat /proc/version
Linux version 2.4.20-18.9 (bhcompile at daffy.perf.redhat.com) (gcc version
3.2.2 20030222 (Red Hat Linux 3.2.2-5)) #1 Thu May 29 07:09:43 EDT 2003
# dovecot --version
0.99.10

I've just recently noticed a serious problem with my system. After about
an hour or so I get errors in /var/log/maillog such as this;
Sep 21 06:40:16 the-system imap(ray): opendir() failed with file \
\/home/ray/Maildir//new: Too many open files

I investigated with 'lsof' and found that many copies of '.customflags'
were open for each and every folder. ie; Each folder's '.customflags'
file was open 15 times!

I suspect that postfix is not able to store newly collected email while
this is occuring, therefore I am likely losing messages.

I've tried with multiple mail clients (Sylpheed & Evolution) and
multiple users, always with the same result.

Further investigation indicates that each time the client scans for new
mail another instance of each and every '.customflags' is opened. As I
have the client set for checking at five minute intervals then it was
probably 75 minutes until the client barfed. Less, if I manualy scan for
new mail a few times.

If I shutdown the client and restart it then everything is fine for
about an hour. Running 'lsof /home/ray/Maildir/.customflags' on the
server I can see the list of files increasing each time the client
checks for new mail.

Any help would be appreciated!