What does Isolating IPC objects under Expert Sandbox settings do

Hi, I have looked at the manual and knowledge base but I cannot find anything relating to Isolating IPC objects under Sandbox Expert Settings.

Does anyone know what this means and the any possible consequences of having this unchecked ?

The only reason I ask is that I read a thread this morning concerning Roboform crashing in IE9 and Chrome which is a problem I have been having too and unchecking this box seems to make it work .

Andy