Hmmm looks like it is Intellipoint drivers but I have never had an issue with this in the past so can't be a driver issue surely?
Don't count on that -- Microsoft does occasionally push driver updates through windows update as well, so it's possible that something changed without you knowing it.
Since this problem didn't start until today and if your OS is Windows XP, then you could try a system restore to a couple of days ago, to rule out any software drivers or settings:
Start -> Program Files -> Accessories -> System Tools -> System restore
If the problem persists after the restore then it is probably not a driver issue.
- Did you check the sensor at the bottom of the mouse to make sure it's not dirty or gunked up? If so, clean with a q-tip or something
- The optical mice often have problems if the surface underneath is too reflective. Did anything change there?
- Do you notice any difference if you put a piece of paper or something under it?
- More farfetched, but worth mentioning: I've seen an optical mouse start getting choppy on a poor quality desk where the surface wasn't entirely straight anymore, but started to curve a bit. Due to the shape of the surface, the sensor wasn't always flush with the desk anymore but hovering slightly over it in places which greatly affected the accuracy
- Did you happen to install any other wireless equipment close by? It's possible for a standard 2.4GHz wireless phone, keyboard, wi-fi router or even a microwave to interfere with the signal of your mouse.
- Have you tried re-syncing your mouse with its base station? Doing so often will get it to scan for an pick the strongest frequency within its range, so it you have interference issues you can often resolve them that way.