My friend bought a 1.1.3 OTB iphone (unlucky) and I jailbreaked it for him.

Here is how I did it:

1. Downgrade to 1.1.1.
Dock you iphone and power it off. Power it on, hold the home button and the power button 10 seconds, and release the power button, don't release the home button till itunes detects the iphone (The screen of iphone should be black, or you will get #1 error). Hold the shift button, and do a restore to 1.1.1. At the end, it will come up with #1015 error, just use ibrickr 0.91 to boot the phone. You have to do the restore to 1.1.1 if the ibrickr turns green.

2. Jailbreak 1.1.1
Doing this using the normal #3001#* method.
Install BSD subsystem and OktoPrep.

3. UPGRADE to 1.1.2
Do the upgrade to 1.1.2, and use 1.1.2 jailbreak to jailbreak 1.1.2.

4. Follow the 1.1.3 jailbreak method in the forum to upgrade and jailbreak to 1.1.3.


Now you have a 1.1.3 jailbroken iphone. The phone function is not working. I tried the SIM unlock myself. It does not recognize any sim card properly, even the at&t sim.

Hi,
This is because of the new baseband 4.03.13g. It locks the Carrier down, so it will not function.
I think because the Jailbreak for 1.1.3 is not a full one, because they don't want apple to plug the hole they have found, so the real jailbreak is under wraps.
I would guess that when the real jailbreak comes out, you should be able to use a sim from the lockdown carrier like 1.1.2 otb and hardware sims but have to wait for a new baseband upgrade to then allow the unlockers to patch the 4.03.13g baseband.

It's a waiting game

Cheers

Edit, this applies to BL4.6