Blogger are having problems again with this error message, which you can get after you publish your posts. Posts are published but just don't show up in your blog. This problem has reared its ugly head before, e.g. to my knowledge in January 2006, but Blogger eventually fixed it, as I reported then.
I don't think it's something you'll be able to fix yourself. It seems to be an issue with the Blogger system, and I can only suggest that if you experience this problem, you report it to Blogger ASAP (the link only works after you've logged in) so they know there's a problem again - the more people who report it, the quicker they'll take heed and resolve it. Good luck!
[Updated 25 August 2006:] Yep, Blogger are now finally on it.