unlocked 2G iphone looked after software download

I bought an unlocked, jailbroken 2G iPhone and connected it to my MacMini computer to sync the calendar. While it was doing this I was asked to update software. I said O.K. and 25 min later the screen asked me to insert the SIM card.
I transferred the SIM card from my old phone to the iphone. When I reconnected the iphone to my MiniMac I received the message:
The SIM card inserted in this iphone does not appear to be supported. Only compatible SIM cards from a supported carrier may be used to activate iphone...

The phone is now 'locked' in a state where the screen shows the picture of the usb cable and the iTunes logo, and only allowing for emergency calls. I tried the sleep/wake reset and holding down the home button for 6 sec. But it stays locked.

What happened?
Does anybody know what I can do to unlock/unfreeze the iphone?
Is there a way to at least get to the ipod functions?

I appreciate your help.
FQS

When you "update" the software through normal iTunes sync, you are basically installing a new iPhone software version...so any software unlocking you've done is gone. Since it is in a state where it still needs to be "activated" - it will not go to the "ipod" function or anything.

This is why you should always do your hacking yourself.