whenever i try to start the game in any resolution above 1360 x 768 it goes to a black window that says fallout new vegas in the title bar. the music plays like at the main menu but the screen just stays black. i have an ati 5770 with the latest drivers and no other games have problems running above this resolution

Try other drivers instead of whatever you are using now. And next time you are asking a tech question here, please include the standard summary of system hardware, and the routine breakdown of the software environment the game has to run in.