Ok... I might have it figured out.
Fired up computer to play just now, fired up USB hub and connected it to computer. Internet takes a dump so I says, "Self, reboot cause you need to anyway, reset the router, go clean your dirty arse up, and come back and play." Self does this but leaves USB hub fired up and plugged into computer. Come back to play and cannot move my head side to side in the game, but TrackIR software shows all is well. I think a similar set of circumstances preceded the last hiccup with TrackIR, soooo...
Don't leave your TrackIR hooked up for a reboot. Maybe...