[Dovecot] thunderbird not receiving new incoming mail: Timeout while waiting for lock for transaction log file

[Noah Garrett Wallach]

Hi there,

I am running dovecot 1.0.10 and thunderbird 3.1.10 for OSX 10.6.7
and I am finding that new imap mail is not coming into my INBOX folder 
on thunderbird.

there is an error message  "Timeout while waiting for lock for 
transaction log file" in the syslog

here is my INBOX .imap dir

~/mail/.imap/INBOX$ ls -l
total 75100K
-rw------- 1 blah blah  1462024 Jun 11 20:17 dovecot.index
-rw------- 1 blah blah 75153408 Jun 11 20:17 dovecot.index.cache
-rw------- 1 blah blah     1464 Jun 11 20:17 dovecot.index.log
-rw------- 1 blah blah   195812 Jun 11 17:23 dovecot.index.log.2

what is the best way to troubleshoot this problem?  what else can I look at?

Cheers,
Noah