Re: RSS 2 Feed not refreshing correctly
It seems to be a caching issue. If you go to "Clear Private Data" (or equivalent auf Deutsch) and clear the cache it should work fine.
I haven't spent the time to see if it is a feed problem or a Firefox problem (NewsFox is asking for the new data, but is not getting it). The feed does have a tag <ttl>60</ttl> which indicates the feed can be cached without rechecking for 60 minutes, even though they put out articles much more frequently than this. So my guess would be that Firefox is just following the feed recommendation.