In helping a friend set up a new iMac, we discovered that his addresses (imported from a G5 running 10.4.11 in case that's relevant) had most first names in the last name field and vice versa. I assumed this was "user error on entry" but when we opened an email from Jim Smith and chose "add to Address Book" it inserted Jim in the last name field and Smith in the first name field. We hoped that "Reorder last name before first" would fix it but that just affects the way the name is displayed - Smith remains in the first name field.
Mac Pro Quad Core : macBook Pro 2.2GHz Core 2 Duo,
Mac OS X (10.6.3)
Yes. It's not the sorting order (although that is how we discovered it) but the field that the name is put into. In my example if I delete the name Smith from the field that it's in it reveals the field name is First Name. So if this sort is set to first name followed by last name where we would actually expect to see Jim Smith we actually see Smith Jim. If we set the sort to be the last name followed by first name then we actually see Jim Smith. The sorting seems to work okay but it is actually that the first name is entered into the last name field.
Hmm.. I see. Quit AB and move these prefs to the desktop, then relaunch AB.
/Users/yourname/Library/Preferences/
com.apple.AddressBook.abd.plist /Users/yourname/Library/Preferences/
com.apple.AddressBook.plist