restoring iphone 4

[getafix]

i got an iphone 4 for my wifw and a gevey SIM to use with it but unfortunately the Gevey Sim did not work because the baseband was not preserved while updating it with redsn0w and sn0wbreeze ios 5.1.1. I have to do an IMEI unlock. now trying to update it to IOS 6 is a problem , i keeps telling me the phone is not for that build. I tried restoring it with ios 5.1.1 but it doest work, it hangs in the DFU mode. I believe its the redsn0w and sn0wbreeze that is the problem( i might be wrong). Any body has any idea what i can do?