Weird 'No Signal' Issue

As the title suggests I'm getting the 'no signal' message pop up at random time while playing GW, oh, and the sound hangs aswell (which suggests its not just the graphics card?).

I'm pretty sure i've not downloaded any new drivers.

I've used speedfan to do temp checks and my graphics card stays between 40-50 C until right before 'No Signal'.

I've had this computer for just over a year now so the PSU used to be powerful enough

The only other thing I can think of is either my PSU or motherboard is getting a bit old...

Or Gw itself has gone currupt?

either way, the opnly way to get the screens back on again is the do a hard shutdown (hold in power button) and restart...

Help?

Well, there's the first place to start. Get the latest drivers for all your hardware. The problem definitely sounds like a driver conflict. (Although it could, of course, be a hardware failure.)

sounds like a video card issue - either a driver fault or a hardware fault, although those are "usually" related to overheating... it could also be a faulty PSU, I've seen that happen before (the 12v rail that has the video card on it can no longer supply consistent juice).

I was only reading about something like this the other day, this glitch affects both Nvidia and ATI cards alike,

I know on the ATI cards it was the drivers, the program that reports back temp and speeds will say its fine, but the card fan was actually slowing down and causing it to crash, which in turn was actually a fault on the 12V+ rail that feeds the card,

What is your system setup, from hardware, ( including monitor ) threw to OS.

I had this issue (technically i still have), but i dont know if its my Graphics card or PSU thats bad.
The only option for me (until i simply buy myself a new computer) is to underclock my 9800GTX+ to:

594 Core Clock
1473 Shader Clock
997 Memory Clock

If i don't do this Guild Wars will crash instantly exactly like yours (lost signal on screen etc) Other games crash aswell but not as fast as Guild Wars.
Druid isle crashes me within 30 seconds, and the only way to fix it is to reboot and do the underclock.
If the 9800GTX+ is underclocked i don't get any errors.
I haven't actually checked if its the PSU or the GPU, since i know no way of testing em.
750 w PSU (Energon) 4x 18 12v rails.