"Tim Mitchell" wrote in message
...
In article , Suz
writes

"John Rumm" wrote in message
...
Ian Clowes wrote:

After a bit of analysis I worked out it was because I used the mouse
right next to the window. On sunny days the light was strong enough
to penetrate the case and confuse the opto sensors. A new mouse with
a darker plastic case fixed it.

I found that once a few years ago with a mouse - it only moved up and
down on sunny days! The solution was to take the lid off it and colour
the inside with a permenent marker pen - put it all back together and
it
worked fine after that!

That is hardly the case here because the "double-click" is being
activated
and it is mechanical rather than optical.

Even "non optical" mice still sense the ball movement optically using
slotted discs.
--
This is true (but besides the point). But the buttons are mechanical and
not optical, and the OP's problem included windows being opened and closed,
which may mean the double-click signal is being generated somewhere along
the way.