I wanted to wait for a bit to be sure this was the solution.
I have an Evoluent Vertical Mouse (which I love) and I uninstalled the Evoluent driver and it seems to fixed the problem. The only thing I've lost is customizing the mouse buttons, which I'm OK with.
I know several of you also have a Vertical Mouse, have any of you experienced issues with the Evoluent Driver?
I haven't seen the issue at all. I'm using the older Vertical mouse 3 with the Evoluent Mouse Manager v3.91, which I assume is the software build code.
I have an Evo VertMouse 4 wireless and am running the Mouse Manager 5.0 with no issues like that. I have never seen that behavior and I have been an Evoluent fan/user for years - since WF2 days.