Knoppix 7.0.1-EN DVD notes & comments

[utu]

@ Karibu

I subscribe to Werner's & Capricorny's explanations.
There is a minor interpretation that you might try.

Perhaps the DVD is finger-printed and some players may be more forgiving.
Examine the shiny side for prints or abrasions.
Even if you don't see any, a wipe of the recorded surface with alcohol
using a soft rag might improve the situation enough your DVD
will work with both players.

I'd try that before anything more difficult.