Knoppix 3.2 flickers on my Laptop LCD Display. (Card:S3SavagePro SharedMemory)

If I boot Knoppix from CD and use the framebuffer cheat ( fb1024x768 ) everything is fine! No flickering.

My question:
How to setup this framebuffer option when I use the HD-Installed Knoppix Version? I guess a config file has to be changed, but because I am a Linux Newbie I don't know which one, where and what to change.

Thank you for your help!