While trying to quad-box World of Warcraft, I can have 4 games open at once logged in and playing. While playing my game is running flawlessly no lag at all on a freshly reformatted machine. The only problem I encounter is within the first few minutes I randomlly get the error. "No Signal" across my monitor. I checked and my video card is running at a stead 40-46 Degrees Celsius. My machine is running Windows XP Profession, and the World of Warcrafts are ran using keyclone. My machine specs are
Code:
AMD Athlon 64 x2 Dual Core Processor 
Running 5200+
2.61 GHz, 2GBs of RAM (DDr2)
.

I can't find anything wrong except 'No Signal' which causes me to manually restart my World of Warcraft. I can however run 2-3 Flawlessly in the same way, without getting the "No Signal" error.

However next to this computer is a computer with

Code:
AMD Athlon 64 Proscessor 2800+
1.80GZ and 2GB of RAM (Crucial).
This computer can do the 3-4 flawlessly without getting the 'No Signal' error.

The only difference is the lesser computer is ran through a shuttle caste that is opened completely, the greater computer is in a tower case that is closed and underneath my desk in a corner. (Which I just noticed is next to an on radiator. The only problem I run into is 'No Signal'. Somebody suggested my Video Card is the problem and isn't cooled enough since I experience no lag or choppy WoW playing, just the No Signal. But my V-Card says it's only running at around 40-48 degrees Celsius which is around 110-115 Fahrenheit.

Thanks in advance