I am also experiencing the same problem after I upgraded to WP2.2. Under Options > Discussion I have “Email me whenever: Anyone posts a comment (and) A comment is held for moderation” both checked.
The emails have the same appearance in my mail client as before the upgrade, e.g.:
Subject: [my site] Comment: “Post Title” (or) [my site] Please Moderate: “Post Title”
Sender: Name
Date: Date
Yet the body of the email is blank/empty.
Do I need to try re-uploading a certain WP file?