Some things to remember when implementing Wireless. N isn't a standard yet, it is a 2.0 beta and thus doesn't work with much. Most people running N are actually just running a 2x2 spacial streaming G. G isn't a good band for residential wireless because everyone has embraced this ISM band. Thus, microwave ovens, baby monitors, wireless phones, bluetooth, all use the same frequencies and 802.11G only has 3 channels to use as a way to avoid congestion.
Ignorant people have downplayed 802.11a for years saying it is inferior but suffers almost none of the interference that g does, and has 13 channels. I guess the higher the letter, the better, right? Take a look at the SSIDs you see in the air around you and put your new 802.11g on a different channel.