I tested with downloading from the Seeed github link and was able to compile on IAR6.1 without errors. I did get the warnings (Pa050) however and this appears to be an issue with improper line termination (CR/LF vs. LF only). HugeMan may need to look into this as what was submitted to him compiled without hiccups of any kind.
We may also be in for some version confusion now as there are two github sites with Nano firmware sources as well as one Google code site with obvious overlaps. I can also envision it being difficult for a new Nano owner to locate and find pre-compiled firmware and assess what to use. Unless confusion is the strategy here, some consolidation and cleaning up may be in order.