AFAIK there is no advantage to 6.2.1; it may even be a downgrade, according to some posters here (6.2's what I use.) Nevertheless, you could most likely do what I think you're trying to do, except it sounds like you did a "full hd install." That is really only useful if you're going to re-master (make your own DVD) - otherwise, it simply leads to problems like you're describing, because Knoppix really isn't well-suited to running that way. Better to install Debian, if you want to go the hd-install way, seems to be the watch-word.

What specifically do you want to get out of the "upgrade?" It may be that you're better off with what you had. You may also want to look at how to use the "poor man's install" (using tohd or the flash-install program) and then fiddle with the boot arrangements, perhaps as Capricorny describes here.

Anyway, good luck, and let us know how it goes!

Cheers!
Krishna

p.s. Thanks for the kudos! I agree that the tone of this forum is outstanding - that's why I try to add what I can.