Hi Khaled,
This caused by the execution only find swimlaneImpl in its own scope. If it can't find the related swimlane, it won't propragate to look for swimlane defined in parent scope.
I don't very clear for the swimlane behaviour between parent and children executions. So I think I could create a patch and make some discussion about this.
By the way, please use zip to compress the attachment, not rar.