I have the AT&T carrier logo after I jailbroke my 3GS with blackra1n to 3.1.2.
If your carrier logo went missing with the Baseband 4.26/jailbroken 3.1 problem, does it re-appear after doing a 3.1.2 official update? If so, does it disappear again after doing a blackra1n jailbreak on 3.1.2?
Cheers
What does MIM do?
It allows you to change the carrier name at the top of the screen to whatever you want it to be. I had it set up as my name for like a day, then got bored with it.