Thanks LarryBrewer for the help. And the exhaustive response! So helpful. In then end, this came down to my lack of understanding about efficiency. I had no idea there were 4 types of efficiency. It's all spelled out on the very calculator I used...

Forgive me for cross-breeding forums here, but I started this conversation on Homebrewtalk: http://www.homebrewtalk.com/f36/og-pretty-far-off-but-all-numbers-right-426132/ The conversation there let me to wonder if maybe there's a bug in the recipe calculator or if I'm using the Brewersfriend...