Why does twitterfeed only fetch the very last item of the feed when updating and ignores other new items?

I'm currently fetching a number of feeds and sending them to twitter and ping.fm via twitterfeed. Sometimes twitterfeed updates faster and sometimes slower. The problem is, specially when twitterfeed takes a long while to update, more than 1 new item may have appeared on each feed, but twitterfeed only fetches the very last new item on each feed and passes them on. I also realize that it's possible to change the number of items twitterfeed processes each time, but that would result in the new items being collected into one single item, cluttered and rather useless, so I don't believe that's the option I'm looking for.

Basically, I would like twitterfeed to fetch and post all the new items in each feed, one by one.

I'd appreciate any suggestions!