xAuth is Now Working for Me
The good news: I got xAuth working against Twitter this morning - my mistake was stupid - you have to double encode things, and I wasn't doing that. So that's good. The bad news?
This server (and the one over at Cincom) is running on VW 7.6. My first try at backporting ran into a number of small problems, so I've decided to take the other route: updating the servers to 7.7.1. It's probably a good idea anyway :)