Video-Out and LCD only exclusive?

[doppelfish]

So, here's what's been bugging me with my A30p and a co-worker with his
T40: When the TP is connected to the LCD projector, it is impossible to get
it to send the VGA signal to *both* the LCD and the projector via Video-Out.

This goes for X11 (XFree86) on my A30p and on M$ Windows on the T40.

Interestingly enough, I've been able to simultaneously drive both the internal
LCD and the LCD screen on my desk.

Is this an inherent limitation of the graphics hw used in the TP, or what
difference between my LCD screen and the LCD projector should I be
looking at?

cheers,
-- fish