[DjNDB]

I see what you mean. I don't know what causes it, but we can keep trying some things to figure out what could be wrong.

Please try if running the game during a clean boot helps.
(I hope you can work with this, since i can't translate it for an Italian windows)

Booting clean in Windows Vista / 7:
1. Click Start --> Type msconfig --> Press Enter
2. On the General tab, choose Selective Startup
3. Uncheck Load Startup Items
4. Select the Services tab
5. Check Hide all Microsoft services
6. Click Disable all
7. If running the game on Steam, re-check the "Steam Client Service"
8. Click on OK
9. Click Restart.
10. After reboot, run the game to see if it works.

After performing the necessary steps, restore your settings by doing the following:

1. Click Start --> Type msconfig --> Press Enter
2. On the General tab, choose Normal Startup
3. Click Ok
4. Click Yes, when asked to restart your computer