OK, Spark, I got this again and here's the deal: It happens when I get a popup PM notification. I deny the option to read in a new window, then accept the option to read the PM (in the current window) ETA: My bad, I have the order backwards...It's: You have a new private message. Sender: XXXXX Title: xxxxxxxxxxxxxxxxxxx Click OK to view it, or cancel to hide this prompt I click OK, then choose the option to read in current window. That's when the 404 message appears. Here's the 404 Not Found screen capture: Here's the current URL for PM's: http://www.bladeforums.com/forums/private.php Hope this helps!