Mouse thinks its alive (GE wireless optical 97990 rev.4)

My system is a Toshiba running Vista and is less than 6 months old.
Problems with mouse are:
1) If not in use, it occasionally wanders the screen, usually to the left.
2) it jumps all around the screen if I'm using it or not
3) whole sentences disappear
4) it backs up and starts typing in the middle of the sentence
5) it freezes in place and when it comes back (on its own) it jumps (re-appears) anywhere on the page
Now then:
1) when it works, it works well
2) turns itself off if not in use
3) batteries die no quicker than in other devices (I use nicads)