I updated Podpress to version 220.127.116.11 and since then, it doesnt generate the whole feed anymore. What is missing are the iTunes tags, and most important - the enclosure tag.
The feed is here http://wissenschaft.wanhoff.de/?feed=podcast. You will see that in the last two episodes I entered the enclosure tag by hand. If you jump to "<title>WWWW vom 27.5.2013: Fleischkonsum, Cholesterin und Alkohol im Auto</title>" you will see how it worked fine for years.
I suspect a conflict with wordpress?