Before an accidental forced shutdown in my PC, all videos in YouTube are played in the Flash Player. I forced it by joining in then leaving out of the HTML5 Beta Test by YouTube when it changed some videos to HTML5 before. Then, when my PC crashed, I got the problem back again. The HTML5 trick doesn't work anymore, nor does erasing cookies and cache in the Chrome browser. In Firefox, Flash is default.
This is really frustrating, as I use Magic Actions for YouTube extension in Chrome so I have more control on watching YT videos. I disabled all extensions and it's still a problem. I want to force it all to Flash. Unfortunately, I can't find any solution in the web. They all say the HTML5 trick and deleting the cookies and cache.