I have a real quick tip for you today, that should help more than a few of you having Flash problems with Firefox. If you ever notice that Flash files or videos are not exactly working right – you might want to first update the RealPlayer. You can download the latest version from real.com.
Once you reach their website, double-click the installer application that you downloaded and follow the instructions.
Another solution you might try is to downgrade Flash. If updating the RealPlayer did not help, and flash files are still constantly crashing, you should uninstall Flash 11.3 and downgrade to Flash 10.3.
Hope that helps! If you know of anymore Firefox flash fixes – be sure to leave them in the comments!