Well, I bit the bullet and bought another box. Live was on my memeory card. I plugged inthe machine, inserted the retail disk and bosh, connected, without having to setup or recover an account or ANYTHING. Weird.
BUT, I can tell you this. Looking at MOTOGP theres a lot changed on the front end from when i was in beta (adverts and stuff). Makes me think that blocked users are flagging up to the wrong/dead server as a result of changing from beta to retail (perhaps BEFORE the required 15th?)
Anyway, i now have 1 x box in an arcade cabinet playing dedicated MAME. One for homebrew applications, and one dedicated to online play....