If I click continue then firefox freezes and needs to be shut down via task manager. If I click stop plugin the message just pops up again after a few seconds. If I restart firefox then the message carries on coming up. The only way I've found to get rid of it is by restarting windows. After that it usually behaves for a couple of hours before the message starts popping up again. This means I keep having to restart windows.
Updated shockwave and flash player to the latest versions but it's still happening. OS - Windows 7 home premium. Firefox 20.0.1.