I jailbroke yesterday after running Tiny Umbrella to keep 1.59 baseband and upgrading from 4.02 to 4.1. That was all successfull.
Today I realize my WiFi distance is crap. I kinda remember it not being that great since I went from 3Gs to 4 but it is real bad now.
I do some research and hear that others have had the same issue, JB or not.
I compare distances against my Jailbroken 3Gs and the JB'n 4. 3Gs goes twice as far. My 4 even gives out 1 floor up in my house.
I call Apple, tell them, yes I have restored, yes, yes, yes. They say, OK take this case number down, go to an Apple store they will swap it for you. Great, make appt for 1 hour from then. Start the process of restoring to original 4.1 (I know I will get a new iPhone with 4.1, but a new one with 4.1 with which WiFi works is better then a JB one with the old baseband that WiFi does not).
ANYWAY, I have restored through recover mode 4 times and DFU mode twice and each time it finishes, it gives me an error that it could not restore my phone. It has restored, but not the baseband. So sometimes with the 1004 error. My TinyUmbrella is all closed. I am totally using iTunes and IT'S OWN 4.1 download. But I do use TU to get it out of recovery mode at the end of the restore and check it after it activates and AGAIN each time 1.59 baseband.
Others are having same issue on ModMyi.
Anyone see this? Anyone? I cannot take it back to Apple like this. Are we all screwed?