Computer reboots when playing a DVD?

my computer very often reboots when i try to play a DVD, it doesn't reboot every time, but probably 70% of the time. what happens is as soon as i put in the disc, it recognizes it, pulls up the automatic program (interactual player for xp, and xine for fedora) and the second it should show the first frame of video there is a loud click from somewhere in the computer and it does a hard reboot, like as if i hit the reset on. i really thought this was a driver/codec issue until it did the same thing in fedora. it has no other issues playing video or reading from the drive or burning dvd's, any ideas?