Out of scan range.

Hi Im having problems with my new screen, where at boot time i get a message "out of scan range 37.1KHz 50HZ" And only when KDE has started and i get the login screen the piccture shows. I cant even go into BIOS cause i dont see anything until its booted. What can i do about this? I had problems with my old screen also like when i shutdown via the kmenu the screen switches off and doesnt come back on. i had to type "shutdown -h now". Also if i change the resolution with SAX when i get to the test window the screen switches off and now {crtl alt del} or {ctrl alt bs} helps. Anyone knows how to resolve this? Thanx