It happened now two times that I wanted to update an IRR by a Dynamic Action. It just did not worked! The Dynamic Action fired (I saw that by debugging with Firebug and APEX) but the Report did not update. Finding the solution costs me some minutes/hours!
Reason: I assigned no Region template to the IRR (User Interface > Template : No Template)
Solution: I created a new empty region template and used that instead of "No Template".
Reason: I assigned no Region template to the IRR (User Interface > Template : No Template)
Solution: I created a new empty region template and used that instead of "No Template".