Some slight progress on the Samsung X10 with Geforce 440GO. The NVidia driver works when I connect to an external monitor, though still not on the built-in panel. I'm very keen to get it working properly to use in my work on real-time computer vision.
I'm now using the 4363 version of the driver. It seems like the panel on this laptop does not agree with Linux very well at all and the problem is there rather than with the graphics card.
Connecting the laptop to an external monitor before boot, booting into Linux and then starting X with the NVidia driver the display comes up fine on the external monitor, very fast 3D and all. At the same time, on the internal panel I see something which obviously resembles the display in terms of overall colours but looks like the sync is way off leading to horizontal patterns. Interestingly (?), with the XFree driver although the flat internal panel works OK it doesn't seem to drive an external monitor properly. With either driver still, when I quit X the console display does not come up properly on the internal panel.
I have tried some of the different driver settings suggested in the NVidia README (EDID stuff, FlatPanelProperties) but with no apparent difference.
Would be very grateful for any more help.