There is a setting for handedness in Windows (or at least there was in Windows 7). The most visible change was that context menus appeared on the other side (so that they don't appear under the hand). But if there is some kind of disabled touch zone near the stylus pointer it may be that it's in the direction of the hand as well.

It does. Hit the Windows button and type "pen" and go to "pen settings" and you can change it there.