Deletes all QuickTime and Flash Caches. Flash Player AssetCache, Flash Player macromedia.com and #SharedObjects. If you encounter problems viewing QT or Flash videos, deleting these caches will often resolve the problem. At the very least, it will eliminate bloated caches.
When QuickTime movies don't display video but you can hear the audio, try removing the 'QuickTime Plugin.webplugin' file.
To remove the file, click the 'Yes' button on the confirmation dialog box and your 'Internet Plug-Ins' folder will open.
Relaunch Safari before testing a movie.