Things that I can think of that might cause issues like that:

* Background window doesn't think it is still foreground (option in the slot config)
* FPS too high, too low, or VSync isn't behaving
* System resources are struggling to keep up
* Rendering library/driver issues
* Chrome is being a memory/cpu hog (again)

Though, with wireless mice, the biggest issue I had was positioning of the receivers. If they're not right next to each other, I would get wierd "spikes" of movement that didn't match. Hard to describe but probably similar to what you're seeing.

If you have ISBoxer, I'd highly recommend trying to use that instead. I think it took me about 3 days after switching from hardware to ISBoxer in WoW to be done and uninterested in looking back.