[Banshee-List] Why won't podcast notice already downloaded podcasts?

[Kevin Bowersox <kevin oonian com>]

On a new installation of Linux Mint 17.2 I configured Banshee to use a
podcast directory in which I had already downloaded many podcasts while
running Banshee on my old computer. Now when I subscribe to a podcast it
shows no archived shows, even though they are there in the podcast
directory.

Is there any way to make Banshee see those existing podcasts instead of
downloading copies of all of them?

Thanks.