Apple Mighty Mouse trackball not working?

I had some trouble with the Mighty Mouse scroll functionality suddenly not working. It'd scroll up but not down. I'm running the beta Boot Camp and Windows Vista, so figuring it to be an Apple driver bug I booted into OS X - which I rarely do. Well the same scrolling issues showed up there. That led me to suspect a hardware issue, likely related to a foreign object stuck in the receptacle under the trackball. A little bit of searching later, I came across this tip for cleaning the Mighty Mouse which worked like a charm!

PS: I've never had this happen on either of the 2 Microsoft scrollwheel mice that I use on my other computers. Perhaps something for Apple's trackball design dept. to revisit.