I have a pretty newly installed Ubuntu 12.04, using Unity. My external monitor is 1920x1080 max resolution. In the Unity desktop itself everything looks great. I have an NVidia graphics card.
When I start my computer and get to the Unity greeter login screen the display is oddly formatted and the resolution seems off. It looks like a zoomed view on the larger 1920x1080 screen. As such it crops the login options off to the left hand side of the screen. So I can only just see the edge of the password box for the user I want to log in with.
I can log in with one account by default by blindly typing the password, but I am unable to switch to other accounts.
Is there anything I can do to fix the log in screen display so that I can see the normal login options?
Note: I first noticed it when I changed my desktop background and the next time I logged in I saw the issue.