Okay, after a long search I have probably found the solution or explanation for missing formatting.
I have to correct myself. There is one option in podPress which has influence on the content of the
<content:encoded> element. If you set the option "Aggressively Protect the news feeds" to "Yes" then podPress will remove all formatting elements and converts non-ASCII characters to there numeric equivalents (e.g. ü becomes
ü) in the content of a post.
The option "Aggressively Protect the news feeds" influences all feeds.
Is this option set to "Yes" in your blog?
If you are using (or going to upgrade to) 18.104.22.168 then set this option to "No". Your feed should still be valid.
It would great if you could confirm that.
This is an very old option and it has become deprecated. I will most likely remove this option in the next version.