HELP - Creating Mattes, Alpha Channel, Overlays, etc In PI11

[dearlg]

I have, frustratingly, tried to create mattes, etc in PI11 for use in MSP8. I have used the instructions for color keying found in the PI11 help file, but several pixels of the keyed out color remain in the finished clip. I want to understand the process for these abilities in PI11, but don't know where to look. Are there any good PI11 tutorials anywhere? Any help will be much appreciated