I have had a bit of this issue myself since upgrading to FCP7. I’ll have viewer and canvas set to ‘open’, and have the same problems as you. What I do is set the canvas and viewer to ‘open’ a second time, even though they are already set to open. That usually works. Don’t know why multiclip sometimes doesn’t work correctly. Well, it is making the cuts correctly, but I can’t always see the selected angle until I stop playback or reset the canvas and viewer to ‘open’. Weird.
David Foster
MacPro 8core 2.8 w/ 8GB RAM
FCP 7
OSX 10.5.8