Streaming Video causes system crash

[new2thisstuff]

I've had my rig up and running for 4 months now and it is rock solid, except for one major tick. (Computer specs below)

 

Whenever I stream video from certain sites, my entire system crashes (as in immediately powers down, not just hangs). This happens for Netflix or Hulu, but not Youtube and the like. (And they even happen while running on XP in Parallels.) I can get anywhere from 5-20 minutes into a video, and then poof, the computer is off.

 

This same thing happens when I try to convert videos on my machine for DVD burning or viewing on iPhone. But never so much as a hiccup playing video files in VLC, just the streaming sites.

 

Any ideas on what is causing this?

 

Rig details:

 

10.5.5 installed using Kalyway

 

GIGABYTE GA-EP45-UD3P

SAPPHIRE HD3870

INTEL | C2D E8500 3.16G

 

Memory 2GX2 | TRANS

HD SAMSUNG 500GB

 

Thanks all! Any insight is much appreciated.