painfully loud beep on mouse scrolling

One of our developers periodically experiences
a LOUD BEEP sometimes when he uses the
mouse wheel and it tries to scoll past the
end of the content. We all laugh every time
it makes him jump.

Today I was paid back. I had headphones on
and it happened to me and I can pretty much
reproduce it at will. I minimize my remote desktop
window after bringing OE to the foreground.
I then maximize the window and start scrolling
down like mad before the screen finishes
refreshing.

We cannot figure out how to turn the beep
off and it's not a sound used in any system event
if you check control panel/sounds settings.

My ears are still ringing, this sucks, I have
enough hearing troubles as it is.


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