I can confirm this - I've checked a number of your 'unsupported' modules and yes, clicking in any of them seems to disable page+/- scrolling in the inspector, until you click on a 'supported' module - and not the title bar, you have to click in the module itself.
Also, yes, if there were some way to get finer control with left/right arrows, or some other modifier key, it would be nice - the page+/- keys seem pretty extreme if you have a bunch of modules enabled.
Mind you I usually use the mouse wheel, or two fingers on a trackpad, or my trackball hack (it's called Marble Mouse Scroll Wheel, for anyone else using a Logitech Marble Mouse and wishing they had wheel functionality. Old, unsupported, but still works here on Win8.1 x64). But options are nice:
Beepster I also have RSI issues with input devices - hence my plethora of choices. I find that switching around a lot keeps it at bay. I make my living playing piano (as a performer), so I can't afford problems. I have a mouse at my left hand, which I am getting better at using, and a trackball and a trackpad (and a Contour Shuttle Express) on the right side. I find if I use any one of them too much it starts to cause trouble, but constant switching helps.