To get Flash Player 9 to work in full screen mod mode you need Flash, build 18.104.22.168 , a prerelease of the next version of Flash
On most distros the Stable version of Flash: 22.214.171.124 is available
In full-screen mode on Linux, playing odd-width movies (with screen widths not divisible by 16) may cause a crash.
It basically means ‘full screen Flash works now in Linux’ yaaay!!
Rpm based distros are lucky, they can upgrade with download Plugin for Linux x86 (RPM, 2.88 MB)
Other distros need to uninstall their original plugin and Download Plugin for Linux x86 (TAR.GZ, 2.88 MB)
Extract the TAR.GZ (usually a rightclick and a extract here will do) , then continue on your terminal:
If you use firefox or mozilla run the installer:
It will ask some questions and install flash locally
You can also run it as root (sudo) if you wish, but usually this is not needed.
You can also copy the plugin into the pluginfolder of your preferred browser:
as root (sudo)
cp libflashplayer.so /path/to/your/preferred/browser/plugins/
If all this sounds alien/confusing to you, just be patient for your next update of flash in your distro, which will probably solve the full screen issue.