I also noticed another issue lately.
When I receive PM's, I don't get the e-mail notifications I'd normally get when I receive private messages from someone.
I noticed cos the lettermail icon on the top-left corner of the page had the 'glowing flash' on it to indicate I'd received new PM's. But I have not been getting e-mail notifications, which usually help me get those read over sooner.
I checked my Profile settings, and I do have it set on 'Yes' in regards to "Receive an e-mail when someone sends you a private message?"