Why are Flash applications so sluggish/crashy?
Solution 1:
This is an issue with the Flash Player - the Linux version has some performance issues with playing video.
Your best bet for sites like YouTube that support HTML5 video is to use that instead. (See here for details.) The performance is much better.
Solution 2:
Hardware acceleration in flash for video and graphics is currently only supported on Windows platform. See: http://www.adobe.com/devnet/flashplayer/articles/fplayer10.1_hardware_acceleration.html
Solution 3:
Alternatively you can use Gnash or Lightspark.
Solution 4:
I would hope your using Ubuntu. Its pretty straight forward if you use the installer given to you from the adobe website.
It might just be a low on processing power since flash is processor extensive process, also more ram might help.
Also going to System > Administration > Hardware Profiles and making sure your graphics drivers have the correct settings helps.
:)