for some reason, new episodes that are clearly available in the itunes store do not download straight away when subscribed with a season pass. seems to be a 12-24 hour delay. this is clearly against apple's own season passes FAQ, which states that "Once a new episode becomes available in the iTunes Store it will be available for you to download". This isn't happening, it's delayed, even when checking for available downloads. looking at other posts, this seems like a common problem recently.
http://www.apple.com/support/itunes/store/passes/
"I see a new episode available on the iTunes Store but I've not yet received it.
Once a new episode becomes available in the iTunes Store it will be available for you to download. You can check if you have episodes awaiting download by going to the "Manage Passes" page. Or you can simply select "Check for Available Downloads" under the Store menu in iTunes 8 (or "Check for Purchases" under the Store menu in iTunes 7) to download any unavailable episodes. For Multi-Passes you should check that your Multi-Pass has not expired. This information is also available on the "Manage Passes" page."