Checkboxes have a number of functions:
- During normal track to track playback unchecked tracks will be skipped.
- Your sync settings will normally be set to exclude unchecked tracks from syncing.
- Checked status can be used as a smart playlist criteria.
In this case checkboxes are not the issue. To do what you want you actually need to change the settings for your podcasts under Episodes to keep, presumably changing the setting to All unplayed episodes so that completed episodes are discarded during the next podcast refresh cycle.
Thanks tt2. I do have the setting as All unplayed episodes.
I noticed that those episodes I marked as played, did not get _deleted_ in the next refresh cycle. I even manually refreshed the podcast, but they stayed on. The blue dot went away, which I understand is the played/unplayed status indicator. :-(
The blue dots should go away when the podcast is marked as played.
Each podcast series should update according to the Podcast Defaults, or a specific setting for that series, when iTunes checks for new episodes or you press the Refresh button on the Podcasts screen. If your settings are to keep all unplayed episodes then played episodes should be deleted.
I keep all my old podcasts so I don't have reason to test this behavior, but if you are certain it isn't working I will have a go at reproducing your results. Would be useful to confirm which build of iTunes you have.