Figured it out! Not a bug - just not understanding the new version of Izz.
Don't know if this is a bug, but in my current file (using Izz Win 2.07b.25) I've got 2 picture players into a video mixer into a projector. The first picture comes up on cue, then won't leave. Changing the video mixer doesn't work, and changing the intensity on the projector doesn't work. The image gets 'stuck' and won't change. Have you heard this from anyone else? Did MS send an update that screwed with my work? I tried installing version 2.1 and the same thing happens. Happens on my Vista computer, 8.1 computer, and Win 7 computer.
works as it should here on mac
there is a test file 28cbc3-2-pix-mix.izz