At one of the projects I had a chance to manage, I had to teach an entire teams (3 people) how to do pair programming. I didn't call it “Pair programming” though, as that would have brought on the FUDs, but I just made people work with each other, test-driven development style.
People seemed to be fond with the idea and have acknowledged their belief the TDD has indeed helped them a lot, but after a while they stopped doing pair programming. When asked why arn't they working on something together they responded that “it just seems unnecessary”.
How do you respond to that? do you just let them go on without pairing? This was not a project under my control in the sense of staff, and I don't believe in forcing people to pair, because that leads to unproductive behavior. So they went on doing TDD without pairing. The code was still much better, but they definitely took more time to do it.
My point? there isn't one, really. Just wanted to share that sometimes not everything is a rose garden. be prepared.
Have you met such a situation? how did you deal with it?