I'm running Firefox 3.6.8 on Windows Vista. When a website is using Flash, I often get the little "The Adobe Flash Plugin has Crashed" message in the gray box, but I also get a Windows notification by the taskbar saying that DEP has closed Plugin Container. Certain websites are okay--I have no problem with YouTube. But others are horrible; for example, JCPenney's website has a Flash menu and is completely unnavigable.