Uh, Duh. Ok, I wondered if it was an IR led but now I
know it is and that
it is working because I can get the mouse to move a teeny bit by running
it over dense text.
FWIW I used to get an SGI optimouse to move not too
shabbily by holding it up near the screen and
tilting it in and out of the plane.
Then rotate it 90deg. to work in the other axis
and 180deg to get the other direction.
(When you're Real-Real desperate)
JEA