I know some of you have read this and are thinking this is BS, but I am not lying.
I was forced to update to 3.1.3 a few weeks ago after doing a network reset and having my phone get stuck on the apple logo boot screen. After eventually putting the phone into recovery mode and trying to do a restore using 3.1.2 (which is what I had on my 3GS - and YES I do have a 3GS to the BONEHEAD that thought I couldn't tell the difference), and was denied the restore to 3.1.2 by iTunes - so I updated to 3.1.3.
After the update I lost everything. I was so pissed and depressed that everyday since I was searching for ANY news on the new jailbreak. Found nothing until two nites ago when I found this;
http://mobilesat.blogspot.com/2010/03/iphone-3gs-jailbreak-313-firmwarenew.html
I followed the guys instructions; DLOADED everything he said and DID everything he said. Including the hack to the Windows/System32/drivers/hosts file as he did.
Everything went fine until I did the steps with Redsn0w. On his video, the computer gives you a warning as to whether or not you have the new bootrom or not... My phone just launched Redsnow and did the jailbreak. Once the message came on that it was done and the process would finish on the phone, NOTHING HAPPENED. It just got stuck in a black screen.
So, I put it back into restore mode and searched how to reboot the phone from recovery and found this posting;
http://www.ihackintosh.com/2009/07/irecovery-iphone-recovery-mode-loop-restart/
I dloaded iRecovery and installed, made sure I extracted the contents of the zip file to by desktop and ran it. After following the steps and holding the power and home buttons for 10 secs, the phone rebooted and as I already had iTunes open, it activated the phone.
I then ran Blackrain RC3 and by phone was re-jailbroken and thru blackra1n on springboard I installed Cydia.
I say that I did not have the SHSH file backed up on Cydia as when I had checked Cydia thru Safari AFTER the 3.1.3 update, I did not see the message 'This device has SHSHs on file for OS 3.1, 3.1.2" at the top of the screen. For all I know, since I was accessed Cydia on a non-jailbroken phone running OS 3.1.3 I could not see this. BUT to my knowledge I had never backed these up, they could've been there though.
So, this is what I did. I took the gamble of trying this guys posting knowing that it might not work and worst case scenario I would have had to do another restore and update to 3.1.3 to get my phone working again. When things didn't go as detailed on the Redsnow JB step, I improvised and tried something else to make it work. iRecovery was my missing step. It worked !!!! It IS JAILBROKEN now and I am happy again...
Oh, one more thing. I downloaded F0recast a few days ago and checked to see if my phone would be able to be jailbroke when it was on 3.1.3, and was told that it would not be able to. According to f0recast I was given this info as to the specifics on my phone;
Serial# *****SVQ33NR (hid the first part)
Firmware 3.1.3
Baseband 05.12.01
Bootloader 6.4
Model MC137
Unlockable NO
Tethered NO
I made this post more for the people out there that already had a jailbroken iPhone and had been duped into updating to 3.1.3 by Apple. YES my phone was previously JBd before I updated, and maybe this was what saved me. For those of you out there that did the same update to 3.1.3 like I did, and LOST your JB, try these steps above. Maybe your phone will do the exact thing as the guy on the video... if not, put in in restore mode and try iRecovery like I did.