Boot problem, No Video

[Paul Humanic]

Hi, I just installed Fedora Core 6 on my computer, and when I went to boot it for the first time, it started to boot, but then the screen went blank and my monitor flashed a box that said "outside video frequencies".  It doesn't do anything after that.  I'm running on a very new computer (PowerSpec 512mb 3Ghz Intel) and a CRT monitor (Korean data systems).  My video card is a Via/sg3 UniChrome Pro IGP.  I saw a previous post recently of someone seeming to have the same problem.  I was able to boot into text mode after changing the boot options, and I tried "telinit 5" which failed, and the video driver was already set to "vesa".  Thanks in advance for any ideas that you may have.