Did you perform a "fresh" install of Mint 14?
If you upgraded, try to save off your data and then do a fresh/clean install
What desktop did you go with?
you have cinnamon, have you tried using the MATE version? Maybe your hardware doesn't like that particular desktop
Have you been able to find/install all the correct drivers?
I had problems like that until I got the correct GPU drivers installed for my nVidia Geforce, so maybe it's a driver issue
Linux: Mint 15 Olivia Cinnamon
Box: Intel Core 2 Quad | 8gb RAM | 500 gb WD 7200rpm | nVidia Geforce GTS250