Noel:
There is a huge consumer campaign against voice-overs during end-credits, as well as against squashing of the credits into a small part of the screen (so that they can't be read), together with banners advertising other programmes - sometimes appearing on screen before the credits have even arrived. There is also a campaign against on-screen logos (DOGs, as they are known).
The BBC and ITV say they do it in order to enhance the viewer's enjoyment. But many of us understand that they do it to simply to spoil archive recordings on DVD-R and force purchase of DVD box-sets...
JN
PS: Check out Dom Robinson's views on this subject at:
http://www.dvdfever.co.uk/reviews/r2r.shtml