I'm not sure what caused this, but Hulu, YouTube, and other flash video sites won't display fullscreen flash on my external display. Even if the window with the video is on my external display, when I click the fullscreen option in the flash video player, it automatically pauses the video and starts fullscreen on my MBP's 15" screen. In System Preferences, the MBP 15" is my "main" display and has the dock. The 24" external is an extension of that, or the secondary display. Before, the fullscreen would be on whichever display the window is located. If my YouTube window is on my external and I click fullscreen, it will display fullscreen on the external and vice versa for the 15" screen. Now, it defaults all fullscreen videos to the 15". Also, I have CS5 PS, DM and Flash installed. Maybe Adobe put a newer version of the Flash player in the CS5 install? IDK. Please help! Screenshots of my displays below, if that helps at all. I just want to watch Hulu on my 24". Right image is my 24", left image is my 15".