Mighty Mouse scrolling problem

Here’s a weird problem. Both yesterday and today I’ve had a problem with the scroll ball on a Mighty Mouse where it just stops scrolling down. The ball moves, but there’s no scrolling. Flick the ball in the other direction and scrolling up works fine, but no scrolling down.

Even weirder, this has happened with two different Mighty Mouses. Yesterday’s problem happened with the wired mouse than came with my new iMac. I unplugged it, plugged it back in, and everything went back to normal. Today’s problem came with a wireless Mighty Mouse I bought to use with my iBook. Since it can’t be unplugged, I’ve tried the analogous strategy of turning it off, then turning it back on. No go. Then I tried turning off Bluetooth on the iBook and turning it back on. Still no go.

Then I Googled “mighty mouse scroll problem” and found this discussion. Following its lead, I pushed extra hard on the ball while scrolling around. There was a rough, clicky feel to the ball for a bit, as if something were in there, and I kept scrolling with extra pressure until the motion felt smooth again. When I went back to normal pressure on the ball, scrolling was back to normal. Hooray!

The experience has made me wonder about two things:

  1. Was the unplug/replug solution for the wired mouse a coincidence? Or maybe I knocked the mouse around a bit as I unplugged it and that dislodged whatever was causing the problem.
  2. Is the Mighty Mouse extra sensitive to contamination from your scrolling finger? Do I have to give up salty snacks while surfing the net?