Hello.
I've been forced to use my backup shitty nokia as my phone since 2.2.1 first came out since I clumsily updated and thus upgrading my baseband. Now I found out that I was one of the lucky ones with bootloader 5.8 and managed to downgrade my baseband back to 02.28.00.

However I can't get yellowsn0w to work. I've just installed yellowsn0w from Cydia after downgrading my baseband while in fw 2.2.1. And now I keep getting sim failure and invalid sim errors when I enter my sim. Any ideas? It's a Norwegian carrier called Netcom and I doubt the sim is the problem.

Do I have to do a fresh yellowsn0w install to get it to work? My baseband is 02.28.00 so there should be no problem there.

Did you disable the SIM PIN? YellowSn0w does not worki with PIN enabled SIMs. Also, try to reset network settings

Thank you! I did what it said in THIS THREAD and turned my phone on, entered the pin and then did a hard reset. Now I have a fully working phone! My 3G has never worked before and now I get excellent coverage. Goodbye shitty $20 Nokia.

As a recomendation, disable your PIN to avoid future problems