Rss feed not recognised with domain mapped site

Dear fellow human,

I'm using the domain mapping plugin to get this link: en.minimalswitch.nl to go to minimalswitch.com This is working perfectly. The only problem is that when I do this, the rss feeds doesn't work anymore on the new domain. Or to be precise, you can still reach the feed in the browser: http://minimalswitch.com/feed/ But it doesn't validate (http://validator.w3.org/feed/check.cgi?url=http%3A%2F%2Fminimalswitch.com%2Ffeed%2F) and isn't visible by services like Feedly. So people cannot subscribe...

Any idea why this is and how to solve this?

Tnx, Maarten