USB Mouse freezing for a second or two every minute or so

The problem of mouse freeze ups first started 1-2 months ago. And back then the screen would actually freeze up where only unplugging power to the computer would allow me to shut it down and start over. I was getting several of those a day. I don't recall exactly what cleared up that problem but the hard lock ups went away. I did initiate some earlier "restore" points at that time. But the more common 1-2 sec mouse freezes have lingered. At first I thought it was from dirt on the optical lens because cleaning it or blowing on it would often provide relief for hours. When I experienced numerous BSOD's two weeks ago a bad memory stick resolved that problem...and along with the mouse hang ups went entirely away for several days, the first time that's happened in months. But the problem eventually returned over the past 2 days. At first only a couple of times per day, now up to several times per minute. I can flip the mouse over at times and see that the optical sensor light is not lit for a brief period. I can yank on the mouse wire and make the light go off.

I was planning to get a new mouse but after having no issues for most of a week I figured it wasn't a simple hardware issue. My computer is an 18 month old Dell Inspiron 560 with nothing fancy, no add ons, etc. All I really use it for is to surf the web (no gaming, no heavy duty spreadsheets or office work, etc.). The drivers used are whatever came with it new. The only programs I've loaded since delivery are Avast, Adobe Flash, Malawarebytes, and Ad-aware. Haven't had the mouse hang up once in the past 10 minutes. And just to be sure that no memory issues were still in play I ran MEMTEST 86+ this morning and received no errors. So the memory is still ok.

Any thoughts?

thanks

Brian