I’m finding the same problem myself. It’s not accepting anything with my domain name in it, and using the “not spam” button is having no effect.
Personally, I wonder if some spammers are including the URLs of bona fide blogs in their comments to try and confuse Akismet. It would be fairly difficult to detect — after all, your average blogger isn’t likely to check all (or indeed, any of) the links included in a hundred spam comments, and would just click “spam” on the lot of them.