Common errors

Login errors:
“You are Unable to log in to the user account “e123456” at this time.  Login in to the account ailed because an error occurred.  The home folder for the server account is located on an AFP or SMB server.  Contact your system admin for help”
This can be caused by a number of things.  First check the time on the computer.  It should be syncing with time.apple.com in the Date and Time settings.  If it is off by a couple minutes from the AD servers, Kerberos won't work and many issues will occur.
Network home is not available.  If the location of the user's AD profile or home directory is unavailable, you may get this error.
Could also be the network protocol is set to AFP or SMB and is wrong in the AD plugin Advanced Options. 

Can't change password:
Check the time sync to make sure the computer is synced with time.apple.com.  If the battery needs to be replaced on the computer, do it.  Call the Storehouse for low-cost batteries.  (603-4992)

Firefox won't download items:
A user tries to open a PDF or download a linked file and gets an error telling them that the item could not be saved because you cannot change the contents of the folder. 
Try resetting the download location in Safari first, then in Firefox.  If that doesn't work, delete the file "com.apple.internetconfig.plist" from the User's Library/Preferences folder.