For long I have been having problem with flickering flash videos in the Firefox 4 beta in Ubuntu 10.10 64-bit. Today I found a solution, and I have no longer any reason to use Chrome. 🙂
It seems that the problem with flickering flash videos only occurs with Adobe Flash Player 10.1. So, by installing the beta 10.3 of Flash Player, the problem is now long gone.
I don’t know how you install the Flash beta in the 32-bit version of Ubuntu. But in the 64-bit version you just need to type these lines in the terminal:
sudo add-apt-repository ppa:sevenmachines/flash sudo apt-get update sudo apt-get install flashplugin64-installer
I hope this solution works for you.