For OS X Leopard this worked for me. Cut and paste this command into terminal: /System/Library/Frameworks/CoreServices.f*/Frameworks/LaunchS*/Support/lsregister \ -kill -r -domain local -domain system -domain user
The command ‘man’ in terminal has an annoying feature: it clears the screen on exit. So if you find a command line switch you want to try, when you exit man the detail all disappears. To correct this, change the following line in /private/etc/man.conf: PAGER /usr/bin/less -is to PAGER /usr/bin/less -isX