Some Vista users that upgraded to iTunes 8 are seeing a fatal error crash -- known as the Blue Screen of Death -- when they plug in their Apple devices like the iPod or iPhone. Apple support is saying this could be due to the PC having "out-dated drivers for devices like Logitech QuickCam/Webcam products, Lexmark scanners, or media card readers."
Some people on the forum have found the clash to be with their HP printers. One support staffer is telling people to uninstall their Logitech software to make it work. But honestly... who wants to uninstall something you use just to make iTunes work? And there are people on the boards who say they don't have HP, Logitech or Norton software that still have the problem. Apparently Apple is working on a fix, but until that fix comes, it's probably best to stay with the older version of iTunes if you use a PC.
Check out the full discussion here on Apple's Support Message Boards.