I ran the 3.1 jailbreak, and the update seemed to go fine. Now I can't get it to connect to cell service. There's a little icon in the status bar that looks like a telephone handset with an arrow pointing away from it.

I tried to downgrade to 3.0 and 3.01. I do have the iPhone registered in Cydia and the host entry in place. But it won't let me downgrade.

I need my phone back now. And I no longer have access to a MAC.

Any Suggestions?