What it the difference between Purge All from the edit menu and Clean Database & Cache from the Media & Disk Cache of the Prefereces window?? When do I use each??
Also a bug in AE CS4. The Cancle button in the Cleaning Cashe Media Database Pop up Window doesn't work. It's always grayed out.
AE CS4 on a Mac
Thank you in advanced
They have nothing to do with each other.
The Purge commands clear RAM and the short-term disk cache.
Clearing the media cache database and the media cache itself have to do with the storage of large, long-term files on disk.
Purging RAM is described in After Effects Help here.
The media cache and its commands are described in After Effects Help here.