Hmmmm, mine stay the way I put them...

There must be something strange going on with your medieval2.preference.cfg file where all your settings are stored. My guess is that you need to be under an Administrator account in Windows in order for the game to be able to edit it. If you ARE on an Admin account please post back and I'll think about it some more.

PS. If you have ZoneAlarm or some other security program, that might be the culprit.