Thanks zacs and eliipsis. I can see now why DVDs were produced years ago in regional versions but I can't see why older films, released on DVD are still coded. The Guns of Navarone, et all, were made many years ago, so hardly need any protection now. And as universal DVD players are now so widely available, I can't really the reason why new DVDs need protecting either.
By continuing this daft practise of coding only seems to add to the confusion.
I have an even bigger problem. Some friends in America have sent me a wonderful DVD all about my favourite architect, Frank Lloyd Wright, but I can't see how I can play because it isn't in PAL format, but NTSC instead. Any help gladly accepted !