I know that earlier versions of photoshop (and possibly even up-to-date-versions) had their own drivers to integrate grafic tablets into their controls - that might be the reason for this behaviour, even if those added tablet drivers are no longer needed with modern windows versions. Because in earlier windows, they had to modify standard windows drivers for the mouse to integrate those special checks for graphic tablets and graphic pens.Oh I meant, just have Chrome/Photoshop (100% guaranteed with photoshop) open and running in the background while playing the game. It tends to make Mouse Systems not work in RM for me.
That mixup between input methods still causes problems with RM when installing tablet drivers which use legacy methods, but to change those problems all programs (including RM) and all drivers would have to be updated to use the modern input functions instead of the legacy functions...

Sorry for being a pain. I just discovered it was Autorun causing all these headaches.