I was thinking the same thing. My 5.1, 5.3 or 6.2 USB drive will not boot in my desktop as long as I have a knoppix file system on a hard drive partition. The USB always trys to pick up on the onboard files. 6.2 USB for instance trys to load 5.3 files and then hangs. I know its trying to load 5.3 because I can cd into the KNOPPIX directory and the cheatcodes are for 5.3 .