MM7 save game corrupting issue on WIN XP

[Aku]

Hello.
It seems my system is cursed or something, first MM6 caused problems and now 7. The problem I'm talking about is with saving game. The game sometimes refuse to save displaying errors about corrupted save file (which is fine by the way, perfectly loadable after returning to main menu). Sometimes it happens after couple of saves, sometimes right from the start. Hell, I've seen this error even when starting a new game (since the game always create autosave when starting a new game)! Now I'm 99.99999% sure it's some kind of WIN XP problem. I've done some testing on a WIN 98 machine with the same game and it works fine. I've tried everything, every option in config, disabling 3d audio, video acceleration, compatibility modes etc. This happens with or without Mok's patch so it's not the problem.
Anyone here had the same problem and somehow managed to fix this?