Firefox 14.01 freeze when watching video

[Sam Sebastian]

Adobe has discontinued flash for the Linux platform; I think that the
latest version that you can get from them is 11.2 and they will
continue to provide security updates for a while. The way to get newer
flash versions now is to use Google's Pepper Flash (I think that as of
right now it's only available to you through Google Chrome

Here's the firefox bug to add support for it.
https://bugzilla.mozilla.org/show_bug.cgi?id=729481