getmouse doesn't return buttons

1
In my last message I said that getmouse would not return info on
buttons. I'm using Win 2000, three button USB mouse, MATLAB 6.5, and
latest version of psychtoolbox.

None of these code variants will detect mouse button presses:

buttons = 0;
while ~any(buttons);
[x,y,buttons]=getmouse;
end;

ptr=screen(0,'openwindow',255,[],8);
buttons = 0;
while ~any(buttons);
[x,y,buttons]=getmouse(ptr);
end;
screen(ptr,'close');

As a matter of fact, buttons only comes back as a single zero instead
of a 1x3 matrix. x and y come back as they should. i.e. No problem
detecting pointer position.

Thanks again for any help.
Pat