Character encoding problem on feed RSS

Don’t know for sure, but I can see that you are running an old version of WordPress (2.2.2). You really should upgrade to 2.3.3.

I still don’t know, but you’re running the feed through feedburner. Have you tried disabling the feedburner plugin and looking at your feed directly instead of letting it go through feedburner first?

That means nothing, the feedburner redirection would still send the post-feedburner content to the validator.

Also, the feed looks fine to me now. What did you do?