BBC ONE Network idents video quality...

Can anyone tell me why a few of the idents from BBC ONE Network are lacking in quality compared to the copies in the Nations?

It doesn't apply to all idents; only some of the original set have this problem; check Capoeira or Acrobats for example - these have a slight "grain" to them, showing some form of dot crawl around various objects and the logo (the right edge of the logo box during Capoeira shows this well), yet check Scotland, Wales or NI, and their copies are pristine.

Maybe I'm nitpicking, but it does seems odd that idents of sub-standard picture quality were passed for use, and for BBC ONE at that.

...you think that's bad. Take a close look at the purple box on the network BBC 2 idents, and then compare with the Nations.

And it's been like it since they removed the BBC2 URLs. Only Logo, Sticky Label and Fire escaped because the box is part of the action, while Morris Dance was made with a nice new purple box.