try changing the boot settings from lilo/grub or whatever you use. one thing you could try is
which should start you in text only mode. then edit your XF86Config file. Mine is in /etc/X11/ Search around on how to edit that file. be careful or you could ruin your monitor. I dont know too much about knoppix. Your probably going to need the specs for your new monitor. You may be able to get these from windows or from samsung(website or papers that came with the monitor).