Hi Cameronian, had my fingers crossed for you - I guess I shouldn't have uncrossed them.
It sounds like there is some application or process that is causing your mouse to have problems. The next step is to look for what it might be. Did you start up an application in the minutes before the rodent started misbehaving - or even closed one down? Was there something that you did - maybe printed something - shortly before?
Other things to try in order to pin down the problem might include unplugging (from the PC) any devices that you are not using. If all goes well, plug them in one at a time - a couple of days apart to see if the problems reccur.
There are various logging programs - some built into Windows, others as add-ons - which can help pin down the errant process but these are a bit heavy going to analyse. It's a while since I used anything like this but if the worst comes to the worst maybe someone more up-to-speed with these things can recommend a good logger and then help to analyse it for you....
Hope this helps.