Comment 50 for bug 89746

i have tried to 'start kubuntu with safe graphics' and it didn't encounter a problem like 'just a black screen'..
then i installed kubuntu on hard drive while running in safe graphics mode.. after reboot, kubuntu loaded with no problem..
but whenever i alter the screen resolution to 1280*800, the black screen comes again and after any boot, it says 'hi' to me; i cannot escape it..

i think it could be a problem related to vertical refresh rate of the screen.. 'cause i have had a glance at the refresh rate of screen on windows vista and it is 59hz.. on kubuntu, there is no option as 59hz.. briefly, it could be a problem 'caused by monitor driver or gpu driver..

thanks for all comments..