Hi mate, I was forced into a clean install and like you, lost all address book contacts.
Did you save an address book archive? If not you are probably in for some fun
From my experience (this might work for you, who knows), even though I found the meta data cards, putting them back into the current Leopard folder didnt work and I had to use quick look on each file to manually retype the details it conatined! I am starting to think this is an issue between Tiger address cards and Leopard address cards...
You can give it a try anyway. Try getting the data from a couple of places. Firstly your old user folder (from the back up) > Library > Application Support > Address Book and copy all this data into the same location on yout current user (Leopard) folder.
Now try; old user folder (from back up) > Library > Caches > com.apple.addressbook. Copy everything from this folder and place back into the equivialnt folder on your new user account.
Launch address book and hope it works! It didnt for me
If this fails..you can use quick look (press space) on the files you found above ^ to give you your data at least so all is not lost!
Good luck!
