Second Round Chances?

I have a second round office visit with one of the big 4 in a northeast metro area. The first round was on campus and I was notified that I got a second round invitation a couple days later. From most of the people I have spoken to, the second round is almost a sure thing for an offer as long as you don't make any obvious gaffes. Has anyone else seen this to be the case or am I underestimating the situation?

Also, I will be doing the second round at an office different than when I interviewed on campus. Will the interviewer, with whom someone originally speaks with, contact the other office and let them know what they though of you?