I bought a Nano several months ago; I was able to program it successfully. Great. I bought a pair just before Christmas, and gave one to my dad. Got the software loaded onto his computer, but it got the "getsync out of sync" error. Great, nothing like buying a defective gift for the old man. Took it home, and checked the second one: both won't communicate on my laptop. I plugged in the first Nano that I bought, and it programs with no issue. So it's not a software installation on my computer. I am thinking the defective Nano's might be lacking the bootloader.
I found this link: http://arduino.cc/en/Hacking/MiniBootloader which shows how to move the bootloader on the Mini's. I am guessing that the Nano's can be programmed the same way? Same pin connections etc.
Thanks.