If I run the attached project compiled with fpc trunk (maybe a week old), it runs 5 times slower than when compiled with fpc 2.4.4

First question, can someone else reproduce that?

I couldn't find much difference in the output of -al (except some naming convention), so I wonder..

The codepage string routines have been merged to trunk little over a week ago.

I suspect that this is the cause of the slowdown.
It is exactly to get this kind of reports that the merger was done: to expose the code and get feedback.

I would therefor not recommend current trunk for mission-critical code.

But then, that is why it is trunk. You are not used to it maybe, (in fact, neither am I) but trunk is considered unstable for a reason :-)

Michael.