Well, I have tested this now on 3 devices with similar results: the MK808 mini pc with Jelly Bean

Well, I have tested this now on 3 devices with similar results:

the MK808 mini pc with Jelly Bean

Motorola XOOM 2 ME tablet with ICS

Samsung Galaxy SII phone with ICS

I don't believe any of them are incompatible, as I got FF for each from the Play store, and it does work fine except for this one quirk. I had no use for keyboards and mice for Android until I got the MK808 a couple of days ago, and that's when this problem surfaced.