After jailbreaking your device to 3.1.x, you might’ve noticed that your Carrier name is not coming up, you only see the signal bars. Carrier Logo Fixer fixes this, it automatically fetches your mobile carrier name and displays on your iPhone screen. After installing Carrier Logo Fixer you phone will respring and after that, you will your carrier name..
Well there is another way too, most of you might be already aware of this, you can install MakeitMine to Add your own custom carrier (or banner) name.
But once you install Carrier Logo Fixer, MakeitMine will not work (You cant change the custom Carrier name, still banner works 🙂 )
Carrier Logo Fixer is available in cydia for free under BigBoss repo for free.