I certainly agree with OErjan on the burning speed. I'm glad you checked the md5 sum. If the speed of the burn isn't the issue, you may need one or more cheat codes. Unfortunately, I know of no good science to determine which codes work for you. I found I needed knoppix acpi=off noscsi after version 3.3 or 3.4 came out (I forget which). It took me about 6 months to find that (not a full time search, I just used an older version). If those don't help then knoppix nodma helps some people. Otherwise find the list of cheat codes and start playing around with them. You might also try knoppix failsafe. This will disable most hardware checking and you may not be very happy with Knoppix if it does boot, but at least it would be a start and confirm that finding the right cheat codes is what you're going to need to do. Another approach is to try knoppix expert at the boot promt and see if any combination of answers to the resulting questions gets you past the lonely penguin.