Ubuntu crashes (shut downs automatically) when browsing the Web

[Jet]

When I use Ubuntu for using Adobe flash, it may shut down
automatically. I sometimes load pages and it turns off automatically.
It maybe the Flash. I may reinstall Flash to fix the problem. The Web
site I use Flash mostly is YouTube.

It maybe a kernel problem because it shut downs when a problem happens.

Bug report: https://bugs.launchpad.net/bugs/258886