Need help.

At seemingly random intervals my monitors will lose signal and if i wait long enough my computer will eventually restart and the monitors come back up at the windows boot screen. I've looked all over the place trying to find out why this is happening and could not find anything. All my drivers are current and after a fresh install of windows it still happens. Any ideas as to why this is happening and or how to fix it?

Asus P5SD2-X
p4 2.8
3 gigs pc 4200
creative xfi extreme music
Asus en7800gt
600watt ps
36 gig wd raptor
300 gig seagate

possible VGA card error, maybe unshielded plug, etc

Could you elaborate on unshieled pulg? Is is possible for a vga fem to dvi male converter to cause this?