Knoppix 7.0.1-EN DVD notes & comments

[Werner P. Schulz]

The DVD drive within the laptop may be damaged.

[Capricorny]

The DVD drive within the laptop may be damaged.

Surely the laptop drive is to be blamed here. But it may be somewhat complex, in that you may not get errors with that drive and other media. Two pieces of hardware may both be "within specs" relative to standard testing equipment, yet they may deviate from the specs in "opposite" directions, resulting in failure when they are used together. I remember this happened a lot when music CDs were new, shops didn't hesitate to sell returned CDs, because usually, the new customer wouldn't notice the "defects". This is one of the physical rationales for slow CD burning, trying to reduce the variance in the writing process.

[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.