Re: Example of very bad bluescreening.

Have you tried doing a difference key in a precomp? Is there some footage shot of the set before the talent was on camera? (It has to be with the camera in the exact same position as with the talent.) Try grabbing a frame (or looping a small section if possible.) Then you can set that or the talent footage as a difference layer above the other. Don't know how well it will work, but I have been able to use the technique successfully on a couple of occasions. With some more tweaking it can sometimes be used as another matte key.