if you firebug your page , you will see that right at the end of a IR you have this :
<span id="apexir_LOADER" role="alert" style="display:none;"><img src="/i/ws/ajax-loader.gif" alt="Processing Request">
display = none , when nothing is happening .
Hope it will help you.
Hello Ludo, Vincent,
thank you very much for your help. It seems this will enable me to find a way.
Though I must admit that I wasn't precise enough:
There's no Interactive Report but just some plain text fields being updated by Dynamic Actions.
I'm going to inspect the HTML and post the answere here if I can find it.