Michael,
while I could certainly name a few issues, where Apple has - unfortunately- not shown any intention to provide a fix, I'm not aware of a general problem with Address Book in 10.4.x.
Is your Address Book data still wiped out whenever you restart your Mac?
Did Apple Care walk you through the standard troubleshooting procedure?
- Make sure you have an up-to-date backup of addressbook.data . (just in case, - though you can't really do much wrong.)
- "Repair disk permissions" and "Repair disk" using Disk Utility (/Applications/Utilities/Disk Utility)
- Log in from your own account and delete the Address Book cache folders:
/Users/your_name/Library/Caches/Address Book/
and /Users/your_name/Library/Caches/com.apple.AddressBook/
- rename or delete the Address Book preference files:
/Users/your_name/Library/Preferences/com.apple.AddressBook.plist
and /Users/your_name/Library/Preferences/com.apple.AddressBook.abd.plist
You might have to adjust your Adress Book settings afterwards, since they will be set to the default state.
- Log in as Administrator, download your favorite system utility (i.e.
YASU ) and run the "daily, weekly, monthly cron scripts" as well as "clear system cache" and "clear user cache"
- reinstall the 10.4.5 Combo update
from the Apple website.
Restart your Mac and see how it goes.
Good luck!