I've been using Nero 7 without problem for a good while but about 3 weeks ago it started rebooting the PC at 5% during burn. I've made sure I have disc space (45 gigs), defragged, shut down everything I could. If I force the PC into Safe Mode it will work but 1 dvd5 takes almost 4 hours to burn. I've even replaced the burner. Any ideas?