This is how I fixed my screen resolution (default display) problem in Mint 14
Background: When I installed Mint 14 (Nadia) it could not detect my monitor and defaulted to 1024x800 (4:3). It would not detect my 1600x900 dell monitor with vga connector (the only wire provided).
Solution: I followed the instructions in this post on Ubuntu Geek: http://www.ubuntugeek.com/how-change-display-resolution-settings-using-xrandr.html
with the modifications in the notes, below. Please do read the post carefully and try out the instructions in the way they describe before making permanent changes.
Notes: Mint 14 uses MDM (Mint Display Manager), not gdm or kdm, so to make the changes persist the file to edit is /etc/mdm/Init/Default
. An easy way to do this is to navigate to the file using Nemo (the MInt file manager), then right-click on the file and select open as root. Now when you double-click on the file it will open for editing in gedit. Add the lines as described in the Ubuntu Geek post, save and reboot.
When the computer restarts you should notice the splash screen is at the correct resolution but when you login you will have the old setting. To fix this, go to prefences, displays and you should now be able to select your prefered resolution. This should now persist whenever you login. Other users will need to change their resoltion, when they next login. (If anyone can improve on this, please post below.)
If you use these instructions successfully it would be nice if you posted to let me know that they work. Thanks.