I've played a kazillion hours of BTS SP using the 3.17 patch. Just lately the game locks up, usually on a save load. Nothing in my configuration has changed. What worked fine for a long time no longer does so. A normal lock-up would just be a minor annoyance; but now it corrupts the XP operating system so that it won't reboot properly. I need to try multiple times or boot from the CD. Any Ideas?