Make sure the battery cables have very good connections and make sure the cable at the starter has a good connection. On the solinoid wire, make sure your getting 12v. I know you said the solinoid is clicking, but make sure there is 12v there and not a very weak + voltage.

Autozone has been wrong before, they dont actually load test anything. All they do is apply power to see if parts spin.

Edit: oh crap old post...sorry
Terry