Well, 2 days ago, my iPhone ****** up horribly. It got stuck on No Service and froze. Started boot looping, So I restored it, and it came up with unknown IMEI and wouldn't detect a SIM.
Went to the Apple Store yesterday, and it started working right when I walked through the doors. They refused replacement since it worked at the time (well, as far as they could tell, since I didn't have an AT&T SIM)
Rejailbroke and unlocked it, and it worked fine for a couple hours, then did the same thing. So I took a picture of the Unknown IMEI screen.
Went again today, and it was working when I got to the store. So, I showed the Genius the picture and explained it wasn't all the time.
He swapped it out, and I stuck my unactivated AT&T SIM in. Damn, its 4.0.2.
Got home, and figured, MAYBE SHSH are on file with Cydia. Configured the hosts, and it went down to 4.0.1!
Weird thing is, I launch Cydia after jailbreaking and it showed the "Make my life easier" screen (leads me to believe no shsh on file)