Does this happen with a single element?
If it's a different problem than http://bugs.adobe.com/jira/browse/FM-1221 , please raise it in the bugtracker (providing the snippet of code needed to replicate it).
This will allow us to prioritize it and take it into account when during bugfixing.
No, it happen with 2 or more elements,
with a single element (with 3 streams) it works.