Clips only run in the preview, not the output

[appie]

I have several clips that only runs in the preview pane and not in the actual output. Others perform just right. I don't see the difference between the clips, they ar all .mov clips.
I use arena 5 with an mac pro 2.1

please help !

[He2neg]

Any Blackout acitvated ? Layer perhaps?

Opacity from the clips?


Move the non working clip to a position of a working clip and try again....

[appie]

thanks, will try that