What's wrong with this feed?

Hello all,

For a website I'm making, I collect feeds form different sources using FeedAPI.
Everything is working just fine, except for 1 feed.

If I import it in feedreader, it's working correctly, but when I use it with FeedAPI, it seems to work fine, only... it doesn't collect any items from the feed.

This is the feed I'm talking about: http://feeds.feedburner.com/atg-nieuws

Any idea why feedAPI won't collect any items from this feed?

Regards,

Ron