"this message has no content" in Mountain Lion

Ever since I upgraded to Mountain Lion, I often receive "message has no content" for replies to the active email, meaning the one which has been clicked on, and is being displayed. I have to close Mail and re-open before I am able to view the content of the message, though the "no content" error still appears in the email list. Eventually it goes away.

Running 10.8.1, and receiving mail from Exchange 2010. I do not observe this issue with email received by my Gmail account.