I also applied the latest patch and did all the tests with your examples projects and then tried to redo them with two tracks of my own: everything seems to work fine even though some tests with my tracks I don't understand well. :) Nice examples are also ydiff; swap and transition. The chromakey seems to me comparable to CGG's classic chromakey and not avid's. The ability to replace the background via Blend Program is great, though. I am left with the curiosity of combining Chromakey HSV with Blend Program's background replacement, but I will put it off until Monday. Thanks also for the additional insights for the note for the manual; they are all interesting and make one understand some of the problems that have come up over the years (and maybe even find a solution via custom Blend Algebra functions...). I hope others will also test because I am not good as a tester.