ITV are quite notorious over this, watch pretty much any repeat of Morse, Frost or Darling Buds of May, they tend to get copyrighted the year they were re-edited. I remember seeing a Morse that was Copyrighted to Carlton Television in 1992, even though the original edit would more than likely be a Central/Zenith production.
With Darling Buds, it was 'remastered' (well, cropped to 16:9 and a filmic effect added) in 2003 which led to new credits in the then current 'smokey hearts' style, a then current purple Yorkshire Television endcap added and the copyright date changed to 2003 (however the full-length closing theme which made the credits unusually long for the time). ISTR that the rerun in which these remastered versions debuted was slapped firmly in Saturday night primetime and wasn't actually billed as any kind of repeat. Perhaps on this occasion they actually were trying to pass it off as a new series rather than one which was 10 years old at the time?!
There were then further re-edits made in 2006. This time it was re-edited to have 3 internal breaks rather than 2 (with some very unsympatheic cuts made to achieve this), the credits were changed to the then latest house style, with an 'ITV Productions' endcap and a 2006 copyright date. These credits also ran within the official time limits, but there was no re-edit of the theme tune; it just faded out partway through when the credits were done.
Still oddly, the current ITV3 reruns use mainly the 2006 edits, but some stories have 2003 edits used.
I remember a few years ago they showed Classic Coronation Street once or twice on ITV1 during the day, and I remember well they changed the credits to the 2006 look, with the original year copyrighted to ITV Productions, now that didn't look right.
This has started happening on Network's releases of old ITV programmes. Until 2007 the box art would copyright the programme content under it's original year to the actual company which had produced it. But from 2007 they switched to copyrighting it to ITV Productions. This happened with the Upstairs Downstairs box set which had '(C)1971-1975 London Weekend Television Ltd' but the release of spinoff Thomas & Sarah the following year had (c) 1978-1979 ITV Productions Ltd' on it. Fortunately, network are *very* sympathetic to the actual content of the disks, retaining original frontcaps, endcaps and even break captions if they still exist on their source material.
I've seen very weird examples with the late 1990s Thames logo (after it was taken over by Pearson) with '(c) 1973' at the bottom.
Even more odd is that the tapes delivered with the late-90's Thames logo on the end still had the original Skyline frontcap at the start. So they removed the period branding from the end of the programme but not the beginning. Odder still, there were a few examples of programmes having a skyline added at the beginning which were produced after frontcaps were dropped and so wouldn't actually have had one originally
Why did Thames' programmes have to be presented by other franchises when they first became an independent producer?
Until 1998, only franchisees had direct access to the network. Thus all programmes made by independents had to be a production 'for' a franchise holder which then 'presented' the programme to the network.
Even when a franchisee produced programmes through one of their own subsidiaries, they still had to make it for the parent company and then present that to the network. Thus The Sweeney was a Euston Films production for Thames Television and Inspector More was a Zenith Production for Central.
Rather more silly examples followed when ITV stations got taken over and their production departments split from the broadcasting operation, technically leaving the production department an independent producer which had to producer the programme for the broadcasting franchise which presented it to the network. Thus, for a while in the Mid 90's all Central programmes had 'Carlton UK productions / A Central Programme for ITV' whilst everything from LWT had 'LWT Productions / An LWT Programme for ITV'.
Since Thames was such a well known name and of course is the only independent producer which previously held a franchisee, it just became a whole lot more obvious when the Biill was suddenly 'A Thames Television Production for Yorkshire Television / A Yorkshire Television Presentation for ITV' Rather ironically, Carlton ended up become the 'presenter' of pretty much all Thames programmes, and until they bought Central out, this was pretty much the only network exposure their name got.
The system was later simplified to allow direct access for independents but with the requirement for a 'compliance licencee'. As mentioned earlier, this was more often than not Channel Television.