LCD goes black for 3 seconds then turns back on??

[Elusiv1]

I just built a computer from my father and he's having problems with his LCD(Samsung 906 19") losing signal for 3 seconds. He tells me that the computer freezes where the mouse is unresponsive?? Could this be a driver issue or maybe something i have to adjust in power settings? I did use a VGA to DVI adapter for the VGA cable, so i told him to buy a DVI cable for a direct connection to the DVI port on his 7800GT, maybe that has something to do with it. I'd appreciate the help, Thanks..

Here are the specs on the computer:

AMD 4800+ Socket AM2
Abit AN52 board
2GB OCZ DDR800
250GB Maxtor SATA drive
Hec Power 525W PSU
BFG 7800GT OC
Samsung 906 19" LCD