Turns out it wasn't a case of disc rot. According to the brief blurb sent with the discs it was a reaction to the inks used on the labels.
As for the speed of delivery I was pleasantly surprised too. FREEPOST is usually second class (expect it when you see it) so the turn around was extremely quick. Mind you, they only came from Cwmbran (pronounced Coom-bran - for those not au fait with Welsh), which is only just down the road from me.
BTW I mentioned this problem (and how to resovle it) on another forum. One contibutor, though, thought the address to be a little suspicious and suggested one ought to contact MGM Home Entertainment Customer Services, which apparently is what he did. So, should anyone have any reservations about sending their discs to the FREEPOST address, send your discs (with a cover letter) here instead . . .
Customer Services MGM Home Entertainment 5 Kew Road Richmond Surrey TW9 2PR
