Thank me later ;P After one of the inGame supporters offered me help, I updated my ticket. While waiting for an answer, I asked another bounty hunter if I may join him. I went into his instance, and logged out while standing next to Pirrell. After logging in I was able to at least complete the Droid factory quest and continue my story line. I still got the Talk to Pirrell quest, but at least I can go on now...

I doubt any upcoming patch will fix this. This looks more like something they need to change on players who already have the problem. A patch will only prevent it for new players.

Kinda the same problem here: I'm stuck at Pirrell. First time I was able to open the door by killing the robot. Then Pirrell gave me a quest. But it was the following quest. I tried resetting the first one, but now I am not able to open the door anymore. I got both quests in my Log now. That seems to be the cause, because the game thinks I've already completed the first one and there is no need to open the door anymore...

Still got the problem. Can't talk to the robot, the door won't open and so I can't even talk to Pirrell... Friggin sucks, cause im already lvl 29 and can't do the class quest which started on Balmorra.