Nested workflow task activation

CMSILuser

TS 6.1 SP2 on Win2K

This is regarding child workflow activation. I am testing the OOTB author_assignment_with_nested_job.wft which invokes author_assignment.wft

It works fine as it is. In this workflow wftask is next to a submit task.
If I substitute submit task with a user or external task, No task in the child workflow gets activated. I mean, child workflow gets invoked but no task is active in the child job.

If put the submit task back in place, it works fine.

I am not sure if there is any sequece limitation for wftask? Please let me know if you need further details.

All inputs on this are very much appreciated.

Thanks much in advance.

Note: I couldn't find any similar issue in my initial research on devnet or support. So I am positing this to see if any one noticed this behavior.