> since 2 days our firebird server crashes. Server log:
>
> DBSERV02 (Server) Thu Jun 16 09:57:06 2011
> Database: D:\FIREBIRD\JENZBASE.FDB
> internal Firebird consistency check (invalid block type encountered (147), file: exe.cpp line: 1010)
>
>
> I can't figure out why. No updates, nothing changed. Hardware (chkdsk) seems ok.
>
> Perhaps someone can point me the right way to locate the problem?

Looks like http://tracker.firebirdsql.org/browse/CORE-3389.

Make sure you handle errors at transaction start and not pass zero transactin handle into queries.

Regards,
Vlad