I'm running Xubuntu Oneiric (11.10) with an nVidia GeForce GT520 (according to lspci):
I've got 2 screens connected (VGA). Not only is the maximum resolution of the monitor wrongly detected (1024 x 768), but xrandr also can't find my second monitor.01:00.0 VGA compatible controller: nVidia Corporation GT520 [GeForce GT520] (rev a1)
I'm trying to get DualHead running - and I'd like to see if I can avoid the proprietary driver...
Just for the sake of completeness: Using the proprietary nVidia driver (280.13-0ubuntu6), I see the 2nd monitor and can use it.