CrashedAgain, thanks for your help. The information you provided gave me what I needed to fix my problem -- the removal of the corrupt (?) copy of grub which hung on after the Knoppix installation. I still don't understand, though, why grub defectively remains on the HD and takes over the boot process, supposedly after being overwritten by another distro.

Regarding your comment, "[the] post is #5 on the google search list": Thats good news, as others will be able to easily find your most helpful contribution.

Thanks again.