Some of you have updated to Mac OS X 10.5 (aka "Leopard") and found that you could no longer upload episodes to your podcast! Turns out this is a bug with the Flash player for the Mac. We've been looking into it, and found the following knowledge base article from Adobe:
File upload using FileReference.upload fails in Leopard. End users are unable to browse to the file to upload.
That's the problem! They have posted an update for the Flash player which you can download here. Keep in mind that this is not the final version, so you may encounter other issues still.
For more information, check out this blog post from Adobe's Peter deHaan.
If anything else comes up, we'll let you know.