Jim
Thanks for your response. Victim of what?
A Google search brings many examples of people with apparently a similar problem. At least one of those had tried reregistering with Adobe, but it did not work in that case.
I am suspicious about a flaw in their registration system, as I remember having to re-register the whole CS6 after a short time (1 month?), even though I am ~100% sure that I had properly registered it the first time. Just how the product's functionality was kneecapped back then, I don't know, but some things did not work and others were compromised.
Last time this same Acrobat X problem happened, it immediately followed the automatic Adobe update of Reader. I then removed Reader, presuming that Acrobat would cover its functionality - but if I were to reinstall Reader, at least I might be able to OPEN a pdf! (Though not manipulate it in the way that I need to).
Whatever the problem, I don't have time to research it, and will have to resort to trying to achieve my aim using a tortuous workaround with a laptop and MS Word involved. It would be easier if I could have CS6's Indesign running on the laptop, but I only have the one licence. I still need suggestions for a solution to the Acrobat problem though.