I'm actually not sure about that... I've never installed the UCKB1 stock 2.2. I do know that it comes with 3e recovery and it's more difficult to root because of that. I looked into it a bit, and SuperOneClick will root a stock 2.2 Captivate, or so it says. It does sound more simple than the RootzWiki version. Here's a link to the app: http://forum.xda-developers.com/showthread.php?t=803682
Let me know if it works!
Let me know if it works!
