Problem caused while added a 3rd power port on a 3rd side. Originally complained about an illegal internal block, then crashed when I deleted the power port in an attempt to see if I had placed one behind it...

http://pastebin.com/B1ETD5YL

Great job so far on the mod.

Thanks for the report, I'll get on this ASAP.

Ugh, oversight on my part when fixing the FMP weirdness. I can easily fix this tonight when I get home, it'll be in 0.2.12A2.