Well, that's the problem you see. I discussed this on the legal newsgroup several years ago. ( Peter Crossland might recall this , I think he contributed) . At the time someone was questioning the fact that they had received a replacement licence from the DVLA which had removed categories from their licence. I had changed my licence because I had a burglary. I got one of those new picture ones - which I still have.
Now my old paper one had stated I passed a test in an automatic but my new picture one didn't mention this at all . It gave me all categories manual and auto. I know the advice from legal was to say nothing because I might end up having to retake my test ( as the DVLA gad told the biker he had to re take his test, even though it was their mistake).
So I have this licence which actually says I have a manual licence but I know I learned in an automatic and so I wont drive anything else. I learned to drive around that magic date - so that is all important and I don't know which I have now.