Just to clarify this: http://www.swtor.com/community/showthread.php?t=607614
In short, you now can't hear a companions casual talks (i.e. when you come to a new planet) when you are running or not facing him. I've actually thought it was a problem on my side, but it seems like it's not just me (people responded in the thread above that they have had similar problems). Started after 1.7.1 obviously.