It's probably the lxml requirement that's causing a problem on Windows. I'm going to get rid of that dependency in the next version because the amount of XML being parsed is really really small. Doesn't make sense to have that whole package installed for such a simple thing.
I actually haven't tried any of the sensor stuff yet. I was just following what was written in the Roku External Control Guide. It would mostly depend on the running app to know what to do with those messages anyway. I might try to install Angry Birds or something and see if I can get the controls to do anything weird by sending sensor calls.