You say that as if you didn't want it to.
I don't know...whats the problem with it?
Getting back to your original problem I had a think and definitely remember having the same issue not so long ago....in a galaxy far far away...
I think, and I'm not 100% sure of this, that I had to uninstall the mouse, reboot, and let windows install the mouse again.
This doesn't 'update' the driver as such but does install it 'after' PS so its not been knackered by the PS installation.
I've not had the problem since but couldn't guarantee that's what I did....it does ring a distant bell though.
That's the trouble with fixing Adobe issues....there's just so many of them they all tend to roll into one!
Anyway, needless to say if you try that make sure you know your keyboard shortcuts to reboot your machine....the mouse will be disabled after uninstall. Best to do this with nothing running except background services....that way if you get stuck you can always hard reboot via holding the machines on / off button for 5 seconds, (if you don't have a 'reset' button), without it moaning too much about being shut down 'improperly'.
Again, no guarantees but another thing to try if it happens again.
Thanks for the update on your progress. 
Regards.
MrToM.
