Windows 7 - Win 7 DVD unreadable - all others OK

I'm guessing this is best placed in Hardware, but I'm a bit mystified by this...

I was helping someone out with their PC , and they have a strange problem:
They have installed Windows 7 Ultimate, but following installation the Windows 7 DVD cannot be read, in fact the drive doesn't even spin up. The PC has a Win XP installation on a separate disk which also cannot read the Windows 7 DVD - the drive spins up and attempts to read but goes no further.

However, the PC can read all other DVDs, and the DVD can be read on all other PCs.

So I've concluded either the DVD drive is on it's way out and the fact the Windows 7 DVD is affected is just coincidence, or Windows 7 has some copy protection which operates at a BIOS level.

I'd appreciate any views on this

Cheers
MiF