is ubuntu free ?

Have you resolved your flash issues? Haven't heard from you, so I don't know if you had a flash issue or a graphics card issue, or even if you're issue has been fixed.

Someone earlier suggested Firefox with a YouTube HTML5 plug-in, or Chrome or as an alternative for flash-related issues. I believe Chrome prefers HTML5 web protocols (Google developed it!) to replace flash videos (such as YouTube, which Google owns). I believe someday soon that HTML5 will likely replace the problematic flash. Until then, I've recently learned of:

http://www.noobslab.com/2014/01/pepper-flash-alternative-to-adobe-flash.html

I prefer Firefox (personal preference), but Chrome/Chromium has its merits. I use Chromium as a "backup browser" for certain websites and tasks. Even if you prefer Firefox, as I do, this could potentially assist in future troubleshooting issues on your machine, as well as websites that aren't displaying/behaving properly. Another tool for the toolbox! :-D