I don’t think we have any idea.
There is obviously a translation problem here, you are describing an issue in terms that do not easily relate to FCP. I would hesitate to make any suggestions based on that same translation problem.
I will try anyway.
I believe the renders are being replaced in the background. Turn off background rendering. Make sure your render settings match exactly your sequence settings and your sequence settings match exactly your clip settings.
bogiesan
This is my standard sigfile so do not take it personally: “For crying out loud, read the freakin’ manual.”