Anyone had the 'Invalid Sim' problem?

Here's my story.. I'm currently using a 2G iPhone. I have a spare 3GS from my dad who accidentally upgraded to 3.1.3 with the new bootroom. Nevertheless, 'Spirit' came out and the 3GS its finally free!

The problem now is the 3GS set couldn't read my SIM card.

Anyway to fix this?

Thanks for replying

Is there anyway with guides to unlock for the new baseband?

Good evening,

Is it possible to downgrade from iOS 4 to 3.1.3?

The story goes like this:
-Father sent his 3GS to a phone shop for unlocking(which he succeeded last time)
-The fella said he couldn't unlock it that time(yeah, researched, asked here and there was no unlock for accidental upgrade to 3.1.3 last time)
-One day, I went there and asked for the status of the phone
-He told me that he upgraded to iOS4? And now he couldn't jailbreak or unlock. I forgot which did he say but
-Now the phone is unusable again

And yes, he upgraded without notifying us

Alright thanks

Can't wait for both unlock and jailbreak to come out

Hello, do you guys know how to connect my iphone with file manager programs?

I'm using mac's Fugu or Cyberduck. Both doesn't allow me to access to my iphone and phoneview is just limited

Alright, will give it a try. Thanks