I've tried installing both the Mate and the xfce editions of Mint14, 64bit, both with the same issue. The live CD works fine, but after install, the logon screen is very low-res, and then after a second, the screen goes crazy, like it's getting a bad refresh rate or screen resolution or something. Switching to a command line with ctrl-alt F1, etc... has the same issues. Can't read the text, and get crazy lines across the monitor.
My graphics card is a NVIDIA GeForce GTX 560. Never had issues like this before--help!