It must be some ad blocker or something, but I can't view videos. I can't seem to find what's causing it. I can go to YouTube and watch a video, but when someone posts a link, I am unable to make it play. I'll get a site with a black rectangle where the video is supposed to be. Happens on links from tweets too. Safari and Firefox both. I tried the Flash uninstall/reinstall/disc permission/restart routine twice.