Mostly, I stalk you using the RSS Reader Panel extension for Mozilla Firefox, which doesn't like it too much when you introduce new fangled features into the RSS XML. It's a bit strict but that's a good thing.
You can get DTDs to validate your RSS XML against (run it through a tool like XML Spy, or write a perl script to do it) but DTDs are fairly limited. Be nice to see an official XML Schema for the various versions but I'm not aware of any...
Andy B
Paul Clarke's blog - I live in Hythe near Folkestone. Married to Clare + dad to two, I am a full-stack web developr, and I do js / nodejs, some ruby, python, php ect ect. I like pubs, running, eating, home-automation and other diy stuff, history, family tree stuff, Television, squirrels, pirates, lego, + TIME TRAVEL.