I joined companions after Farkas showed me where to sleep. He gave me a quest right after it "Trouble in Skyrim" I went and killed bandit leader, guess what? Whenever I go inside Whiterun, quests completes itself without allowing me to talk to Farkas. I cannot do other companion quests because NPCs think I should finish my work with Farkas. Wtf is going on?

I am having the same problem trying to complete "Trouble in Skyrim." I killed the bandit and the bandit leader and returned to Farkas, who had an arrow over his head, to turn it in and Farkas doesn't acknowledge anything and I can't continue with any companion quests. They all tell me to finish my task for Skjor. I have no idea what that is. I talk to Skjor and he says I am a whelp who has to prove myself. I did notice it the "Proving Honor" quest it isn't marked that its completed even though I went back to Jorrvaskr and became a companion. So annoying!!!!