[ltp] Presentations with t61 + nvidia graphics

[Micha]

I have a  thinkpad t61 with nvidia graphics Quadro NVS 140M and I'm trying to
figure out how to show overhead presentations with it.

I managed to connect an external monitor using the nvidia-settings programs in
twinview mode.
I can set the external screen next to the original one but then acrobat in full
mode (and everything else in fact) stretches to both screens instead of
maximizing to one screen only.

If I set them one screen over the other the state of things is a bit better but
I can't set the external screen to the internal resolution (it's limited to
1024x768 and the internal one is 1680x1050) so I don't see the whole screen and
the internal screen won't go down to 1024x768 (says that it is an unsupported
resolution despite appearing in xorg.conf).

Is there anyway to make this work? (do I need xinerama or something enabled)? I
am using debian unstable with xfce desktop if it matters.

Thanks