HELP!! Please! Ubuntu 9.04_64bit

Okay so I downloaded Ubuntu 9.04 64bit version and I believe it is awesome!!! Couple issues with it though. I only need to go into one right now though. I downloaded a multi-verse game called warsow. For some reason when I played it my monitor couldn’t read the signals it was sending and it said something like mode not supported or something like that. so I restarted and when I did my resolution had gone from 1440×900 to 1024×768. Now I can’t raise the resolution higher than 1380×768. its really obnoxious because now i have a blurry image on my screen and i was so happy with ubuntu and i don’t know what is wrong somebody please help