The BenQ M310 is an excellent little RF optical mouse that I bought for use with my M100 and my iBook:

(it takes two AAA batteries and the RF transceiver slots into the little flap outlined in silver)

After upgrading to Tiger, it stopped working correctly. After a couple of months, I finally figured out why: according to this discussion thread at Apple, it's incorrectly being recognized as... a graphics tablet in versions 10.4.0 up to (and including) 10.4.2.

Apparently USB Overdrive fixes the issue, so I decided to put up this Wiki node as Google feed for other folk to know.