I'm going to guess your problem is that you have the camera's built-in flash set to Commander Mode. Commander Mode works by sending little pulses out to the Nikon speedlights to set their exposure. Problem is, one of those preflashes is potentially enough to trigger the slave on the B1600, so it fires before your camera opens its shutter. You're going to need to trigger all of your lights the same way, either with a PC sync cable, a radio trigger (e.g. Pocket Wizard), or a flash from your camera's built-in speedlight. Higher end Nikon speedlights like the SB-800 and SB-900 have what's called an SU-4 mode. SU-4 is a slave sync, which will cause it to fire when it sees another flash. Unfortunately, that's not something the SB-600 supports. Neither does it have a PC sync terminal, which would be another way to solve the problem.
Put more simply, if you have a dumb strobe like an Alien Bees in your setup, you need to have everything on manual (both camera and other lights) and trigger everything the same way.