As for me first problem that not directly related to my job is communication, but if the conversation connect with project there is no any problem. But what are you tallking about in coffe-break, in lift and so on. For example, I all the time felt mylself little confused when somebody ask me - Are you happy ? In russian meaning of this question is more deeper (maybe this is not correct world) than in English. And really never know what kind of answer give to them..