Podcasts that I have played or marked as played on my iPhone are not showing as played when I sync to iTunes and are not being removed Recently (I'm not sure when it started) podcasts that are marked as played on my iPhone (4 hardware, 5.0.1 OS), when I plug into iTunes, the podcasts are still showing as unplayed on the iphone in iTunes, and so they don't get removed.  How can I fix this?

iTunes 10.5.1.42 on Windows.
This is not an exact answer to your problem, but it helps avoiding it!
I have given up using the Music-App and iTunes for Podcasts. I now use the App Podcaster and I am so happy with it.