......what the Argentinians (and probably the Daily Mail) claim the UN said and what the UN actually said/put down in writing are actually two different things.
Exactly - all these newspapers saying "UN says disputed Falkland Islands are in Argentinean territorial waters" have missed the fact that the CLCS have specifically said that
"With regard to the recommendations in respect of the submission made by Argentina, it is recalled that, previously, the Commission had already decided that it was not in a position to consider and qualify those parts of the submission that were subject to dispute and those parts that were related to the continental shelf appurtenant to Antarctica (see CLCS/64, paras. 76 and 77 and CLCS/76 para. 57)”
In other words, they have only commented on the extension in areas NOT subject to dispute.
Also, the extension in the undisputed areas is really nothing to make a huge fuss about - since there is the option to reserve rights over a larger area than previously, many countries have done so. The U.K. have filed similar claims for extension, based on Rockall. Claims have also been filed for the Falklands/South Georgia/South Sandwich Islands. CLCS has not yet ruled on these, but presumably will also be unable to comment on disputed areas.