A few days ago an app went rogue and leaked memory taking up all 4gb of RAM and more than 8gb of page file space. The result was a machine which was unusable and took about 20 minutes to (eventually) shut down.
After rebooting Safari would not show my "Top Sites", instead showed me a "This page could not be found" (or something similar, I can't remember), would not display the "Top Sites" button on the menu, and the button was not available in the list of buttons to add.
After a reboot this was resolved, but I would still like to know what went wrong.
Does anyone know what could have gone wrong here?