1. Safe Mode is unbelievably powerful,
   - Besides doing an enormous amount of housekeeping,
   it will temporarily stop all non-Apple kernel extensions (and many other items) from loading !
   

   ---

2. This will stop potentially problematic programs from running, some of which include,
   - Symantec AntiVirus, Little Snitch, OpenAFS and Cisco VPN clients.
   - And if combined with the ">console" trick, will give you the best debugging enviroment you could ask for !
   

   ---

3. If your Mac will ONLY work in safe mode,
   you may have a bad kernel extension or the permissions are set wrong.
   
   
   • Make sure they are all OWNED by root and the GROUP is set to wheel,
     especialy items NOT made by Apple !!!!!!
     ls -asl /System/Library/Extensions | more
     
   • To rebuild the kernel extensions, do:
     

   sudo rm /System/Library/Extensions.mkext
   sudo kextcache -k /System/Library/Extensions
   sudo reboot
   

   
   or try sudo touch /System/Library/Extensions, which should work too.
   But removing the /System/Library/Extensions.mkext file is better.
   
   
4. The WiFi on your laptop (not desktop) is ACTIVE in Leopard (10.5).
   - To enable it on Tiger (10.4) do,
   sudo kextload /system/library/extensions/appleairport.kext
   then do
   sudo kextload /system/library/extensions/appleairport2.kext

Verbose and Safe Mode Tips.

1. To do a Safe Boot, you can save a lot of finger holding by temporarily adding -x to your NVRAM setting.
   Reboot and come back later when done and remove the -x and reboot one more time normally.
   
   
2. While you are here, please consider putting your Mac in VERBOSE MODE, via the "-v" switch.
   
   
3. Verbose mode is way cool, you will see text messages at start up and shut down instead of the static Apple logo.
   
   
4. If you want to try VERBOSE MODE just once, just hold down the Command (Apple) and V keys right after the boot chime.
   
   
5. Verbose mode is one of the best tricks to see what your Mac is waiting for at boot time and when you logout, shutdown, or re-start !
   

   See CURRENT settings	nvram -p
   Set Verbose Mode = ON	sudo nvram boot-args="-v"
   Set Safe Boot = ON	sudo nvram boot-args="-x"
   Set Both = ON	sudo nvram boot-args="-x -v"
   Set Both = OFF (factory default)	sudo nvram boot-args=""

   
   
6. The above will work for Panther, Leopard and even Snow Leopard.
   - Please be VERY careful adjusting any other NVRAM items.
   
   

• For more detailed power up issues, see my Startup items page.