Archives give me 403 Forbidden error

I recently imported from Blogger to WordPress. Everything appears to be working fine, including posting, but if I try to click on my archives by month, for example, May 2007, I get

Forbidden

You don’t have permission to access /2007/05/ on this server.

Any idea how to fix this?

My site is cheeksofgod.com and I’m running v2.2