I have four consoles in the house, one 360 Slim 250gb, one Elite, one Arcade, and one 360 Slim 4gb. I have two copies of Halo Reach, one has never stopped working and works fine on all consoles.
The other I opened yesterday NIB only to discover that it would not work on any console, so I returned it to the store today, got a new one with the same results. Again the old copy works fine, but the copy I picked up today will not work.
I have to think the disc was stamped wrong, otherwise I would think at least one console would read it. The consoles range in age from new to launch units. Additionally, no other game disc in my collection is having a read error on any console.
Edit: I should add that I have tried pulling the HDD's, swapping in new ones, etc.
[Edited on 11.30.2010 6:28 PM PST]