The chain, chainring and cog were all brand new. It was a wipperman 152 chain, and vuelta chainring. My problem sounds exactly like what 11.4 described. Its possible that, with a different chain, the problem wouldn't have occurred.

EDIT: Actually, rereading 11.4's post, that wasn't quite the problem I had. The problem that i had was the tooth profile on the cog had a ridge that would catch on the ends of the narrow links of the chain when the tooth was in the wide link. this would lift the chain until the tension built up, the snap the chain back onto the cog. It was worse when I put backpressure on the chain. I blame gravity for that.