iPhone 4 ios 5.1 with gevey turbo Aircel sim possible?

[Max2extreme]

I own an iPhone 4 GSM with Gevey Turbo and Aircel sim with IOS 4.3.3. All was going well untill my brother updated it to the new IOS 5.1. Now I can't use my sim; is there any possible methods of unlocking? It shows "No Sim".
I was able to jailbreak it and using the different apps. It's basically an iPod now....sad. Please help!

 

[Thomasjtsi]

Unfortunately, no. In updating to iOS 5.1 it updated your Baseband to 4.12.00. There isn't any way of Unlocking this BB. Sorry.. :-(

 

[Max2extreme]

So will everything work fine if I downgrade to the 5.0.1 ios?

 

[Thomasjtsi]

So will everything work fine if I downgrade to the 5.0.1 ios?

There's no way to downgrade. Even if there's was a way... you can't downgrade an iPhone's Baseband. Sorry... there really aren't any options. :-(