Re: debugging emacs

[Richard Stallman]

    yes, this was example of correct behavior. The problem is this emacs
    does not work this way if I try to do this for two frames which are on
    two separate displays. Say I select text on one frame and try to unselect
    it on another frame. (it does work for two frames on the *same* display
    though).

    any idea what/where could be wrong?

I am not sure what the reason for this is, but I suspect
it has to do with the code in mouse-show-mark.  You could
study what happens there.