My computer looses the mouse!

I took a guess and put it under software, but I don't know what this might be.
I've a weird mouse problem... I was just using my computer one day when suddenly the cursor began "lagging" and the internet page began jumping up... Then the cursor stopped responding to the mouse... I restarted and the mouse still didn't work.. I shut the computer down, waited a few seconds and turned it on again, still no change... Only when I completely shut it off, including disconnecting it from the electricity does the cursor comes back to life.
Whenever it stops responding, when I go to control panel>mouse and go to the Hardware tab I see that there's no device listed there.. After doing the above the device is listed there again.
I can't point out when it happens because it appears to be random. Every time it happened I was using the internet, but then again I do that half of the time so I don't know if that has anything to do with it..

What do you think? Why does my computer looses the mouse?

I have Win XP professional,
Albatron K8X800 Motherboard.
It's an optical Umax mouse and it's not connected through USB.

 

have you tried another mouse to eliminate that as the problem?

 

Not yet.. I was thinking about going to my dad's house tomorrow and plug mine into his computer and see if that happens.. or switch mouses for a few days...
I guess it might be a loose wire in the cord but I'm reluctant to jump to that conclusion because if it were a loose wire the mouse would come back to life after some screwing with the cord.. That doesn't happen..

I might open it later to see if I can spot anything but for now I want to consider other reasons..

 

Consider that first and test the mouse with a known good one. there is NO reason to jump to any other conclusion until you can eliminate the mouse as the cause first, unless you like to convolute situations that are already difficult to diagnose.