I foolishly upgraded the software via iTunes on my 1.1.4 unlocked iPhone on T-Mobile which made it unusable. I followed the downgrade tutorial on i-Clarified and I got it back to 1.1.4 but in the tutorial it says I also must downgrade the baseband as 2.0 has a newer baseband so I used Pwnage tool to downgrade the baseband and ZiPhone 3.0 to unlock it and jailbreak it. After it was all finished I put my t-mobile sim in but in the top left corner it reports 1 bar signal which doesn't allow you to make any calls or anything like that which is the devices main purpose. I've tried restoring it twice and unlocking it a few times but this is still the same, I assume this has resulted because of me upgrading to 2.0 but it's back to 1.1.4 and I just can't use it and don't know whats wrong with it. I bought it in April so it's not that old but since it's unlocked I can't take it to the Genius Bar or anything. I'm desperate as I don't have a phone at the moment, any help please?