As far as I know, the SC-17 is functionally the equivalent of a very funny-shaped hot shoe. So if the SB-700 is not set in commander mode, it won't be triggering the remote. If it *IS* in commander mode, I would guess that you have not quite gotten the SB-700 seated properly on the SC-17, or perhaps the SC-17 is not perfectly seated on the shoe. (I do not know how many times I've gotten the flashes only mostly seated, but it's not just once or twice... And usually it's good enough to do most things but not something specific...)
_____ Brian... a bicoastal Nikonian and Team Member
My gallery is online. Comments and critique welcomed any time!