Goran,
Yesterday, I:
1. uninstalled the TBM and removed all TBM folders, and then did a fresh install.
2. had a flight and after shutting down, checked the "maintenance log which came up as a blank log and didn't crash XP.
3. refreshed the O2 bottle in order to perform some cheap maintenance (cost of the maintenance showed up on the window but when I selected "maintenance log" I got a CTD again.
4. saw your note about AI so I eliminated all AC from the AI count and didn't enable WT3 during session, refreshed O2 bottle again, amount showed in window ($40 x 2=$80 total), selected "maintenance log" I got a CTD again.
5. all permissions are correct for the TBM900 state folder files (seems to be where the maint log is).
Brent