Meerkat
Most of the time Meerkat is really intensely cool! It's one of the few places I read day to day. Anyhow, there are a bunch of sites for which they provide totally bogus links which is irritating. I don't know if it's their fault or the fault of the sites--and I don't really care a whole lot....
What's really irritating is that on the about page for Meerkat (http://www.oreillynet.com/pub/a/rss/2000/03/17/about_meerkat.html) have a section the bottom that ask for suggestions, bugs, comments, and other feedback and point people to their O'Reilly Network RSS forum. You click on the link to discover the forums are closed indefinitely and "new improved forums will be coming in the near future".
How am I supposed to help out and make the service better when there is no feedback mechanism I can use to tell them there are problems?