The hunt for the hobbits?

[Fat middle]

I don't know if we have been over this before, but I found I little problem (it's really a bit of nitpicking) while re-reading Gloin's tale at The Council of Elrond:

"Then about a year ago a messenger came to Dáin, but not from Moria – from Mordor: a horseman in the night, who called Dáin to his gate. The Lord Sauron the Great, so he said, wished for our friendship. Rings he would give for it, such as he gave of old. And he asked urgently concerning hobbits, of what kind they were, and where they dwelt. "For Sauron knows," said he, "that one of these was known to you on a time."

I think it doesn't match with what later was told in UT: The Hunt for the Ring.

Gollum would not know the term "Hobbit," which was local and not a universal Westron word. He would probably not use "Halfling" since he was one himself, and Hobbits disliked the name. That is why the Black Riders seem to have had two main pieces of information only to go on: Shire and Baggins.

Besides, I've just notice that Gloin places the first visit of the Back Rider "about a year ago". That's far before The Hunt for the Ring had begun as it is told in UT.

I think that Gollum had been captured by that time, so that wouldn't be a problem, but Sauron had not won the Bridge of Osgiliath yet, so the Ringwraiths couldn't have crossed so soon. The only idea I have is that the Rider that visited Dain was Khamûl, because he lived at Dol Guldur, but it is odd anyway.

Have any of you heard anything else about this?