I have an iPhone 3G with the rare 05.08 bootloader that I (sadly) upgraded to 4.2.1. It now has the baseband 05.15.04 is not unlockable. I installed Fuzzyband 4.1-1, but it (without additional cert) said that my iPhone 3G could not be downgraded even with the 05.08 bootloader. Why? Is it because it is missing the 05.15.04 cert? I then tried to fix this by uploading a 05.15.04 to the Fuzzyband directory. Fuzzyband now tells me I can downgrade to 05.13.04 which is unlockable. Is this the correct fix? However, I am unsure if this is SAFE to do so. I know that downgrading from an iPad baseband still leaves the idevice with screwed-up 3G and GPS. Is my downgrade known to also have problem with 3G and GPS? Help!