I raised a data error report with the GRO about this seemingly duplicated registration, I gave both parents names, told them there is no record of another Woodcock-Weir marriage and that it appeared that these two entries were a duplication.
After a while the log said it had been investigated and no amendment was required. Left with the possibility that there were two Woodcock-Weir couples having children in the same area and time frame, that shed some doubt on months/years worth of research.
So I bit the bullet and sent for pdfs for both entries.
Am rather cross now as it IS the same child , same parents, same address, same birth date (though the informant on one was the Dad and on t'other it was Mam). Apart from the surname in the father and mother columns, which in the first was originally down as WILKINSON and later amended to say Woodcock.
I suspect that Dad, who registered the first entry on 4th December, did not notice that the surname was incorrect. He'd have taken at least a short cert away with him, shoved it in his pocket and probably dashed off to work.
The error must have been noticed later and on 17th December Mam went along and informed the registrar, who altered the first entry and re-registered the birth.
As there is no indication on the old index scans, I raised this query with the GRO and they didn't think it relevant to indicate re-registration and the error was the registrar's in the first place, I have emailed the GRO requesting a refund for one of the pdfs.
I am not holding my breath, but at least will give it a go, these things are expensive enough without paying to see errors made by the service that is now making money from it:-)
Boo