If you upgrade your iPhone 4 to iOS 5 firmware your baseband will also upgrade to 04.11.04 [confirmed]. iPhone unlockers know very well that baseband upgrade means they will lose their precious unlock . So you must make sure that your baseband is preserved during upgrade .
Currently there is no public release for iOS 5 , so it’s the right time to aware iPhone users to Save there SHSH Blobs using TinyUmbrella Version 5.0 .
We have already covered several upgrade tutorials in the past which can serve as reference for iOS 5.0 upgrade process . Using Custom iOS 5.0 ipsw through Snowbreeze or PwnageTool is the Safest Method for doing so .
Please Share this post with your friends and ask them to save their SHSH Blobs before Apple drops iOS 5 .
More about iOS 5 Firmware Features .