No Luck at all
Best Suggestion,
1. I have iphone 3GS 3.1.2 baseband 05.11.07. Bought from eBay pre jainbroken and unlocked with Blackra1n. ( you have to always keep blara1n installed on your desktop or anywhere in your harddisk partition in order to reboot this perticular device.)
2. The first problem I faced on a very first day was - I mistakenly rebooted the phone to avoid calls at night. Woke up in the morning. It started with recovery mode ( it simply goes into recovery mode today also in attempt to reboot).
3 . So solution to get rid of the recovery loop. iRecovery - does not work at all. I dont use MAC laptop or desktop , if you have that , best luck.
4. So went on to youtube and studied a dozens of videos for the same loop avoidance and upgrading to 3.1.3 to 4.0.
5. I tried to upgrade this device with sn0wbreeze latest version.
and successfully able to creat a custom ipsw of ios 4.o ( not going for
3.1.3)
6. I had to put the phone on DFU mode - did it successfully. (videos are there on you tube to learn how to DFU )
7.
www.saurik.com website has a trick or tip to bypass the apple signature server to talk to saurik server with an ip address and corresponding server name to update your host files on windows operating systems. I did that before my attempt to restore and upgrade to ios 4.0 from itunes.
8. I did that too. I have encountered two diffrent errors in two independant tries. error 1600 and error 1604.
9 one of the above error has something to do to contact apple actual signature server as well as your usb cable which you receive when you buy an iphone. Yes may be usb cable evenif it syncs your iphone but cannot update your ios , this is wierd but fact.
Conclusion:
One of my friend who is expert in iDevices has a very good suggestion for me and all that IF YOU BOUGHT YOUR IPHONE 3GS 3.1.2 BASBAND 05.011.07. FROM EBAY OR OFFICIALLY JAILBRROK AFTER NOVEMBER 2009. APPLE HAS CHANGED THE SERIAL NUMBERS TO SOME XXX40XXX SERIES ( >= 40 ).
These iPHONES are only be jailbroken and unlocked with blackra1n or blacksn0w from cydia.
There are many many issues which are not addressed by apple on ios 4.xxx
3GS has all the features unless multitasking . Just for multitasking you should not take a risk to permenantly loose your expensive device.
Stick to 3GS 3.1.2 BASEBAND 05.11.07. Do not accept any update from itunes or simply check the box on start of itunes to not ask me again for such device firmware updates and you are safe. However you can update your itunes to any latest available ( it is 10.xxx now as of today Sept 18 2010).
Well Guys ! if you have found any other way to update your ios 3.1.2 with baseband 05.11.07. kindly post it here.
Best luck
Twix...