ECS RS400-A MB - having problem connecting USB External Hard Drive

O thank God I am not the only one with this problem. I have exactly the same. I have also noticed that when this happens, my USB keyboard does not function.

I would dearly love some opinions on this.

Maybe we should also see if there is any commonality in our systems.

My mobo is an Asus M2V
The hard drive in question is a Seagate one.
My pc runs off a UPS.
I have windows XP sp2.

For the sake of those who google this problem and, like me could not find any coherent advice, let me share how it was eventually solved:

Symptoms : Screens switch off, but cpu stays on, or remains running. usb devices do not respond when this happens (like caps lock on keyboard)

This will be more prevalent when the computer is cold (first on of the morning). There might also be other symptoms.

Cure: Take out graphix card and cpu heatsink. Open up heatinc cover for graphix card fan. Get a bottle of compressed air form your local PC shop, and a nice new paintbrush with softish brissles. Proceed to clean out muck from fans and heatsinks, and use compressed air and brush to clean off the circuitboard off the card. Also give the motherboard a once over.

Replace and switch on.

Note : follow good static electricity prevention steps when doing all this.

The fault seems to be cause by a microscopic short in the system on the circuit board. a small hair, or salt molecule or carbonized incect leg or whatever. Dont laugh! this happens more that you know! You wont see it, but betyween the air and brush, you will move it. And of course cleaning out your heatsincs is just friggin common sense. blow your powersupply clean while you are at it also.

Cheers!
Piet