How big is your monitor? (I would try to find all of the specifications for your monitor.) What is the 87 you are referring to, is that the horizontal scan rate in kHz??

I have had some old monitors that wouldn't run 1024x768 with knoppix but I could do an install and get them to run at 1024x768, so I ran them at 800x600 with knoppix and started with knoppix screen=800x600.

Also if your monitor won't run at xvrefresh=60 don't use 60 use another number for the 60, a value your monitor will run at.

CheatCodes can be a necessary part of knoppix.

~rock