When I tried to access the KeyMap option in the IDE Settings dialog, I got an internal error and a wait cursor. I killed the Settings dialog and tried to open it again. This gave another internal error. The next time I tried to open it, I got a 'Blame IDEA core' internal error.
Incidentally, many of the the Settings pages prompt to save changes even when no changes have been made (i.e. no controls have been touched).