Crashing scenarios: Youtube videos ending, and opening a new tab simultaneously. That happened while palying a playlist on autoplay, and when playing a video not part of a playlist. Also, listening to Pandora and opening a new tab.
Visual experience of the crash: With the YT crashes, Firefox freezes and never becomes responsive. For the Pandora crash, the whole browser just shuts down and gives me a prompt to report the crash.
How I know it's FP13: I just installed in not even an hour before the first crash. Experiencing 4 crashes within 30 hours, after going 4 weeks without a crash? Very interesting stuff, isn't it.
I could not find a formal way to report a bug, so here is this.
Also, make it easier to downgrade. It's a pain having to get a 140 MB installer package to run one installer that I need, uninstall the new FP, then disconnect from the internet so you don't tell me that I'm trying to install an old version and not giving me the option to continue. If you're not going to test your software extensively to make sure it doesn't crash often, don't force people onto it.
Running 32-bit Vista.
Searching around, I see that you are going to drop support for 11.7 (what happened to 12? I could not find an installer for that anywhere) on May 13th. You should delay this or actually make FP13 stable.
Pandora has, and causes, a lot of problems if your audio and video drivers are outdated or corrupted. Also, if you have RealTek® audio, you're never going to get Pandora to "play nice" with it. Flash Player has nothing to do with either of those.
You can find 11.7 here: Flash Player 11.7.700.279 but I have Vista Ultimate (64bit) with Flash Player 14 (beta), and I can run YouTube videos, post here and in the Apple Forums, as well as checking out a few News sites, all at once... and no crashes with FF 29.