The right mouse button defaults to putting up a popup menu. If you'd
like to change this, you should be able to do this with the filter
events which are marked with the "?" in the dialog. These let you
decide what happens with the event even changing things about it. I
don't have a multibutton mouse in front of me, but you can definitely
prevent the popup, and I believe you will still get the mouse up. As
mentioned, I don't think the middle mouse button will show up. I
believe this is in the works.
Greg McKaskle