This is not typical, Knoppix boots up at 1024x768 on my system just fine and by default. Knoppix apparently is having problems detecting the proper resolution that it should operate at during it's hardware detection and so it defaulted to a safe but lower resolution. You didn't post any hardware information (in this case both your monitor and video card would have been helpful), so I can't say why this is. I suggest that you follow the documentation link near the top of this screen and read the cheat codes section of the wiki. Cheat codes are information passed to Knoppix manually at boot time that help over ride its hardware choices. I believe that you will find codes that let you force the resolution that you want.