[Neil Jones]

I seem to remember reading somewhere that the ident jingle (on the programmes) for Central was added later, as they were doing the occasional "Central presents an ATV show" thing in early 1982, but we know that sort of thing was done live and I think they used the "other" globe for that, rather than this one.

Although since Auf Wiedershen started in 1983, that doesn't apply here.

The audio track thing is the most likely explanation as this isn't the first time that's happened, as stated above.
Unfortunately stretchyvision isn't new either...