Hi there, I use Firefox myself and recently had the same issue I followed the advice from Firefox and set Firefox back to its original settings (without ad blocking running) and I still had the same problem, but then the Firefox guide led me to a link that provide a means to uninstall the latest flash addon (11.0 I believe) and then a link to go back to 10. something, it worked a treat for me and Ive had no more problems, hope this helps.