Hi Kaizen,
I have a similar scenario as yours, where an update in portletA should trigger an event and a value should be updated in portletB.
But this does not work.
I put portletB into application scope and then the SessionRender worked just fine and I could see the value being updated on portletB.
Note that if you are using the SessionRenderer for push between 2 portlets in the same war, they will be 2 different sessions (it's in the docs for portlets), so not quite as easy as if a single application in a servlet environment.
To create a jira, go here and if you don't have an account simply follow the instructions to contact an administrator.
If you are a support customer, there is a much quicker avenue to get a sample application (of course). but if not, it's always good to be an active member of the community and have this access.