Notes only sync in one direction

I asked the same question in the iPod touch forum, but am not getting any replies. Perhaps it's better posed here, since it's really just an iOS 4 question.

If I create a note in Mail on my OS X Mac and sync via iTunes, the note will appear in my notes app on the iPod. The reverse doesn't work, though. No notes that i create on my iPod ever sync their way into Mail on my computer. Why would this be?

Some details:
OS X 10.6.4
iPod touch 4th gen., running iOS 4.1

Any ideas? Thanks.