Still didn't work for me....I have looked at it from every possible angle.
Even went back to Ustengrav. I activated Jurgens tomb and absorbed a dragon soul, and the horn is now floating above the tomb, even though I gave it to Arngeir.
I read somewhere that closing the gate outside might help, I have tried that too multiple times, still nothing.
Anyone else have any ideas? I don't even think I can go back to the save point, nor do I want to with 10 hours or so played since I did that.
*EDIT*
Forgot to mention that there is a red X next to the subquest...."Bring the Horn to Arngeir", even though I did and he told me good job.
