I tried to update my 1G iphone, moving from 1.1.2 to 2.1

Did a complete restore with iTunes then used Pwnage to unlock etc. This all worked fine and my phone was running great in 2.0 EXCEPT - no carrier signal. I then followed another tutorial on how to sort this with another Pwnaging session but ever since then I've been given errors -(6) (1) (1600) etc. Now I'm consistenently getting error (6) and have no clue what to do next to get out of this!

Any ideas please!