>
> Any idea what's going on here?
> How to tell the server to be more verbose on it's activity
> eg. writing more information to the log file.

It simple was a bad select statement missing an appropirate index.
In this case Firebird tried to use the systems file cache which is empty after a boot of course which lead to some kind of disk trashing.

Try filemon at www.sysinternals.com for windows which shows disk aktivity in detail.

Regards

PS: I'm still looking for a tool monitoring on SQL level.