How to stop gnome from forcing me to logoff / logout?

From time to time my Gnome 3 shell or some parts of it are crashing. Gnome sees a time out and is forcing the user to logout **without** other possibilities. *"Oh no! Something has gone wrong."* See [superuser](https://superuser.com/questions/585635/fedora-18-in-oracle-virtualbox-on-windows-vista) for a screenshot. (Fail whale is providing this dialog.) Is there a way to stop gnome from doing that? Since the other programs are still running and working fine... In my case its clearly a timeout, since a scientific analysis eats up all memory and after its done Gnome has a hard time to recover. (I experienced also these crashes, when I was using some (combination of) extensions which are buggy. In that case the probably only or best solution is to not use those extensions... also considering the posts I've read about this.)