::hangs head in abject shame::
Um, I got a C+ in Calc I. That was after I had already taken AP Calc. I got a 4.0 in the rest of my science and math classes, though, and not a single person -- not my pre-med committee, not people I saw for advice interviews, not adcoms -- ever said a single word about it.
Oh, wait -- one person did. My chem professor, who wrote me a really great rec, made fun of me for about 20 minutes.
So no, I don't think that a crappy calc grade on its own will make any difference at all.