iPod Nano 5th Will Not Sync Smart Playlist Containing Podcasts

I created several smart playlists, and added podcast content to them. They all appear fine in iTunes, the smart playlists contain all the right files.

When I sync with my iPod, the smart playlist names come over, but not the files. I have tried updating iTunes and the iPod, then I re-set the iPod. Same problem.

Is there a limitation preventing podcasts from syncing within a smart playlist? The podcasts sync and play fine when they are not in a smart playlist.....