After the mouse grab feature has been integrated, invocation of any popup reverts mouse cursor direction. This is likely somewhat outdated behavior, since neither Gnome nor KDE do it. As noted by ###@###.###:
    Also, when I get a drop down menu of any type, the mouse cursor reverses direction.
    This is not the standard anymore on Gnome and it's rather depressing when I compare
    the latest snapshot to the older one I had been working on.