I can't get my 1024x768 on 60 hz

[Obsessed]

Hi, I'm using knoppix on a computer without HDD
I'm currently working with knoppix 3.1

For some reason my monitor always jumps to a 55hz refresh rate
although I used xvrefresh=60 in the startupline.
My monitor is fully capable of this hz and resolution
(hell even knoppix startup console ironically works on 1024*768 at 60hz here.)

So If someone please could help me, thanks

[Obsessed]

ok never mind I got it
Kano helped me out
noddc xserver=nv screen=1024x768 did the trick