I got a letter from my DO saying that they are doing a backgroung investigation on my case...., If I do not receive a decision after six months tjhat I should call customer service num. Note that it has been more than six month since my interview and RFE and no letter or decision. Does this suggest anything?. What does it me?. What is this background investigation?. I have already scheduled to go INFOPASS this week and do not know if I should cancel my appt or what. Please someone talkto me.I'll appreciate it