iTunes deleting podcasts immediately after download

For the past few months, I have been having a problem with

iTunes. I never listen to podcasts on iTunes and I have set all podcasts to

make sure they aren’t automatically deleted under any circumstances. But now

they won’t stay downloaded. I will download them, they will appear in their

respective file folder and they will show as being downloaded in iTunes- and

them later, they will be gone. The “download” icon in iTunes will be back and

all the files I downloaded will be gone from their folders. It’s every file

going back at least 6 months. What’s the problem? I am running WIndows 7.