On duplicating the scene, the fcurves are probably not copied, or not set correct. Needs investigation!

Will look into this.

Sebastian, it seems you're adding a scene with sequencer as a strip to another scene -- it's not actually supported.

Campbell, can see code in seq_render_scene_strip tries to support recursion but apparently fails because of lack of animation update. Me and Ton are really curious to know if sequencer recursion is expected to work now? Otherwise i would suggest disable it explicitly and stop confusing users.

P.S. "fix" for this issue could be adding BKE_scene_update_for_newframe before RE_BlenderFrame in seq_render_scene_strip.

Discussed with Campbell. Sequencer recursion should indeed be disabled. But i've discovered the whole can of worms when was looking into this issue.
Fix will take a while.

Thanks for explanation. Did't know this isn't supposed to work...

I disabled sequencer recusrion and made some other fixes for rendered sequencer preview in svn rev52044. Don't see any more issues here, that will all be a TODO :)