I have the same problem. I'm using Mac OS X 10.6.2, iTunes 9.0.3 and iPod Touch 3.1.3. My smart playlist for podcasts was configured to play any podcast with a play count of less than 1 and not video. I've added a condition that the Media Kind is Podcast (though I already have Genre = Podcast), and I've called AppleCare twice and visited the Genius Bar once. Each time I've had enough help that I could make it work once, but a second attempt at synching left the playlist on iTunes but not on the iPod Touch.

I've deleted the playlist and re-created it. I've changed from automatic to manual synching and back again. I've tried to drag the playlist from my iTunes list to the iPod without success.

This playlist worked flawlessly on my 5th gen. video iPod (which I no longer own) and on my iPod Touch until this last update.

Does anyone have another idea on how to fix this?