That faucet I tried to repair last week - dripped all weekend. So today I went back to investigate. Took it apart. Put it together. Took it apart. Examined it closely. Put it back together. Michael came over to help me investigate. He took it apart and put it back together. He eventually figured it out.

This doesn't happen very often, but in this case the screw was too long.

Apparently when I tightened the final screw that attached the faucet to the internal stem, the tip of the screw reached the interior ceramic washer and turned it enough to let out a constant trickle of water. You know if you have a constant trickle you should call someone to fix that.

We were able to alleviate the intense friction by wrapping a spare o-ring around the screw before insertion. That O-ring wrapped four times around the screw. Quite an incentive to ease up on the friction. And the dripping stopped too. Perhaps an unorthodox solution, but you have to go with what works for your particular set of hardware.