I can't talk to some NPCs Help!

[Anaharath]

Here's my story: I went to Upper Kordar to see my progress on the Fandor obelisks. And when I tried to talk to the NPC near the pyramid, he simply didn't start any conversation at all. I was just clicking like a lunatic on him and nothing happened...So I tried to talk to another NPCs in the area and guess what, they were all as silent as a fish. The taverns were working, and the NPCs in other regions seemed more "talkative" so I can't work out what the problem is. Any ideas?
P.S I tried installing some patches but the bug is still there.