[Dovecot] Lost email (inbox) TWICE

[Sezer Yalcin]

I have been losing my inbox. It happened twice. (2 days ago and just half an 
hour ago)

I am using RHEL 4.0 with dovecot-0.99.11-4.EL4
System uses sendmail + procmail, dovecot is up and running.

Here is how it happened:
I was using Mozilla Firefox with IMAP.

At the same time, I logged in from Squirrel Webmail in IMAP to the same 
account. Squirrel mail did not show my inbox contents.
And I turned back to Thunderbird and it said, ' an error has occurred and 
logged to system log'
and INBOX WAS LOST!

squirrelmail 1.4.6 and mozilla thunderbird version 1.5.0.7

I checked server log, I see I log in but there are no further logs.
This happened 2 days ago, I was wondering what the hell happened.

I did not have any issues before. However recently we had a hard drive crash 
and all home folders are restored from backups. I assume it can be related 
to this. My inbox and imap folders are all in mbox format. I believe dovecot 
could not write to log or had something unexpected which lead to loss of 
inbox.

There were no configuration issues and all mail system including dovecot 
were working fine. Now it works fine as well, but I believe it will lose 
inbox folder again.

Has anybody experienced this? Any suggestions to recover inbox? File was 
reset to 0 bytes (could be deleted as well), when i did 'stat' on file, 
there was a file with 1 new message, all were lost.

Thank you.
Sezer