Duplicate comment notification

I’m having a problem with duplicate comment notifications ever since I upgraded to WP2. It seems sort of random and unpredictable, but I’m sometimes getting duplicate notifications of comments that I received several days ago. As an example, I received an e-mail notification of a comment that was posted on January 2nd (six days ago). This isn’t just a delayed notification, as I was already notified of the comment when it was first posted. But it doesn’t seem to be happening with every comment posted. Weird (and quite annoying).

Any suggestions as to what might be going on or how to fix it?