Slow Boot/Shutdown for OS X Lion Fix

THINGS TO DO:

A. Repair Permissions:

1. open up Disk Utility.

2. click on your hard drive (Mac­in­hosh HD).

3. On the right hand side click on Repair Permissions.

B. Clear cache:

1. from the Finder's Go menu, choose Go To Folder.

2. Go to this folder: /Library.

3. Delete the Caches folder.

C. Change ownership of root
1. go to Terminal
2. execute this: sudo chown root:admin / 


Note: 
If there are still no improvements with your boot/shutdown times, I suggest you do a clean install of LION.