After a few days of research I came to conclusion that the updates we do to the elements of parent conversation's datamodel via nested child conversations are not working well in Seam. @DataModelSelection does not work correctly in cases where any entity is added or removed from data model. i.e. @DataModelSelection != @DataModel[@DataModelSelectionIndex]. Although @DataModelSelectionIndex works somehow better but then again when adding a new element and you click on the last element, it fails to return the correct index and you've to click twice.
Would you please Review this. I think this is an issue which should be solve before any CR release.
If you think there are bugs in Seam, you must submit a VERY SIMPLE, working, runnable EAR that demonstrates the problem to Seam JIRA.
Note that in this case I highly doubt that there is any problem that I would regard as a bug. But you are welcome to try.