I'm trying to setup dual monitors on a new 10.10 installation. I have an LG w2040 and a Westinghouse l2610nw. The LG works, but the Westinghouse displays an "Out of Range" notice and nothing else. If I try to change the resolution in the NVIDIA X Server settings window and hit Apply the Westinghouse monitor stays unchanged, but the LG picture gets skewed and I have to reboot. I can change the Westinghouse resolution and hit Save to X Config File and logout and log back in and the setting shows as changed without skewing the LG, but the Westinghouse is still dark. They both work fine in Windows.
My video card is an Nvidia 8500GT.
Things are currently set to "separate X Screen", though I haven't had much luck playing with twin view either.