Windos XP BSOD with HP Photosmart usb device attached https://bugzilla.redhat.com/show_bug.cgi?id=524723 has all the details of the problem. I was just testing attaching a USB device to see if it really worked, and tried my HP Photosmart C5580 All-in-One printer/scanner, and the Windows XP box then started getting bluescreens and crashing at random (fairly short :-) intervals. My latest attempt was on a fedora rawhide system with pretty up to date software (qemu-kvm-0.11.0-2.fc12.x86_64), and the crashes still happen. A reply to that bugzilla recommended adding this upstream bug, so here it is.