I presume this bug is related, but i'll mention it here anyway. Basically, if the mouse goes to the very left edge of the screen/window, as soon as you move away from it, testing for a right-click event will return true. This happens in both full-screen and windowed modes, and is with the 'stable' version (not svn).
If i get a moment after work I'll try to knock up a minimal app-code to demonstrate it, so we can see if it happens to anyone else. Not sure if it IS related though, due to it happening in full-screen, but y'never know.
[to clarify: move the pointer all the way to the left edge (as if to go past it<*>), then try to move it just one pixel to the right; this seems to trigger a right-mouse click event]
<*> this is why it looks like it might be related... but again, it happens in fullscreen so it's possible that something else is going on.