The private message notifier does add an extra query for every script that is run. Has anyone added this one on a forum with heavy traffic. I realize this isn't a problem on low traffic sites but on sites that are already hammering the database with queries it adds up.
Note, I'm not saying I'm against adding this. It's a great hack and quite useful. It's just a common issue that I have to look at anytime I put something in that is going to add an extra database call, especially on every script.
