@rosborne979,
I have a desk top, OS X 10.5.8
I'll have to stare at my mouse. I'll be back when I engage my magnifying glass.
It flutters, seemingly, when the macchina is tired. The cursor jumps around.
On flutter with mouse or not, I'll have to pay attention and get back to you, but as a guess, it seems mouse connected.
Meantime, thanks for your catching this, Rosb.