The "can't talk to anyone bug"

[steve22_3]

Hi I'm playing the v1.7 and encountering a lot of bugs. One in particular is pissing me off, I just got the vial for the quest "cold brook" and returning all the way from the land of the elfs to the dwarfs. But after I came all that way, I found out I just can't talk to brook to finish the quest. In fact, I can't even talk to that dwarf behind me too (whom is standing in front of a submarine).

My mouse icon still changes to a talking icon but my avatar will just walk to the waterfall and nothing will happen.. It happened to me before with the guy who offered to let you fight your future self too.... anyone has this same problem? Anyway around it? Thanks...