Hallo.
with RW 6.3 the Feed is again not validated. This was fixed with RW 6 but hier is a new message.
http://feedvalidator.org/check.cgi?url=http%3A%2F%2Fwww.aufdenhundgekommen.info%2Ffiles%2Ffeed.xml
Who or how can fix that?
Have a nice day!
The feed is shown as valid currently. Other items are recommendations, not validation failures.
I had the pubDate tag already deleted and re-entered and surprise 
the feed was validated! Thanks for the quick reply.