Falc, while I'm no computer whiz, I suspect your problem is the X52 itself. Time and again I've come across hearing how someone's X52 won't hold calibration. It happened to mine, too.
There are 3 possible causes that I know of:
1. Lack of sufficient power. Remedy - powered USB Hub (Belkin get's the highest marks)
2. Drivers not installed properly or not installed at all.
3. The sensors just crap out in time. My guess is that this is the culprit 90% + of the time.
Good luck with a fix but IMHO your best long term bet is a CH rig.