MacFixIt reader "Charles" writes in to ask us about the search issue in Address Book:
"I just read your post about Address Book problems in OS 10.6. I have one I am stuck on... I can't search in Address Book. I type into the search field, but get no response. This happens in any group."
A corresponding thread in the Apple Support Discussions yields a possible answer from user "V.K.":
"make sure that you have spotlight indexing on and nothing in your home directory is excluded from spotlight searches. check spotlight's privacy pane in system preferences. if that's not it try rebuilding AB database.
quit Address book and delete the file homedirectory/library/application support/address book/AddressBook-v22.abcddb. then start Address Book and see if search works."