@roger,
Back a few months ago when I had a flurry of computer horrors (after the one when I needed two new memories), including my famous complaint of cursor dancing, white space in response box skipping, mac's bells ringing, and so on - that seemingly turned out complex: the mouse (I had figured out by then the mouse might be involved) and adobe flash.
My point is, I looked at Mac site for a mouse, money!, and bought an apparently barely used one (maybe someone opened the box) from amazon.
Between the new mouse, lovely, and my shutting off adobe flash (another story of no immediate import to Roger), I got the whole thing fixed for $10.00 and postage, which was small relative to a whole new mac, which I can't possibly do.