> this bug I am looking in my log file since 2.04 version. I do not have that amount of data like Stephan but this bug is something that make my day every week or two and this is the only reason I am thinking about other database engine for my application.
>
> Fatal lock manager error: invalid lock id (19936), errno: 107
> INET/inet_error: connect errno = 111
> /opt/firebird/bin/fbguard: guardian starting bin/fbserver
>
>
> My user is very satisfy with performance but this occasionally server crashes make him mad.

Does it corrupts database ?

Try to install most recent version of Firebird. In your case it is 2.0.5 (or upcoming 2.0.6).
Of course, it is better to upgrade to 2.1.4 but this another story.

Note, on Linux most people used Classic, not SuperServer as you.

Regards,
Vlad