Hi Derek,
Do you have a multitrack DAW on the iPod, or are you using nanostudio for that part? I'm just wondering what you use to capture your tracks on the mobile device and do your overdubs.
I use Sonar X1 on my PC as my main DAW but it can take just about any kind of input format, so I could import tracks from most any other kind of DAW that would be available on the mobile device.
--Jim