Sometimes, when I get one page then have a youtube video, my Firefox over Linux (PCLINUXOS) slow down. Sometimes it freeze. Anybody have the same situation/problem? How can I fix? Any special config for solve my problem?

The only suggestion I would have is to check for hardware problems. Firefox has a fairly large overhead (especially if you run multiple extensions) and YouTube videos, as Flash videos, can naturally take up quite a bit of space. I would first recommend trying to clear out memory space.

Also, check to make sure that your OS, browser, and Flash are up to date. To get the latest Flash update, go here:

http://www.adobe.com/shockwave/download/do..._Platform=Linux

From here, select an option depending upon your version of Linux.
NOTE: If you use the first (tar gz file) option, you will need to extract and compile the installer manually.

To update Firefox, use this download:

http://www.mozilla.com/products/download.h...&lang=en-US

Hope this helps!