I am new to Ubuntu 12.04. A month or so ago I had ATI Radeon video card with plugs for two displays, and Ubuntu showd desktop on both. Then I switched to Nvidia GeForce GTX 680, also dual-display cable. But now it only diplays on one monitor. I made sure cable connections are tight; I know they're good cables because they worked with ATI card.
Any ideas how to get my dual displays back?