ARC Mouse repeated freeze then jumps

Another minor, but nonetheless annoying and recurring problem. Even while CPU usage is very low (2%-8% of Core i7-975), frequently the mouse pointer freezes for 1 or 3 seconds on the desktop, then jumps instantly to where I was trying to direct it before it froze momentarily. There is randomly 2-10 seconds of proper mouse-pointer functioning between the freeze-up/hesitations. It keeps doing this repeatedly for as long as 10-15 minutes at a time. And it often happens when there is little or no applications load on the system.

I checked Norton by chance it was running a scan in the background... nada. I checked "processes" and "services" running and found nothing unusual. I checked the batteries in my wireless Microsoft ARC mouse and they are full-charged.

Thanks!

Could anything in/around the house be interrupting the wireless signal, such as a mobile phone??