3.1.3 iphone downgrade to 3.1.2? is it possible really?

[Roy]

3.1.3 downgrade to 3.1.2?
someone said use spirit to unlock it with 3.1.3 but dude, i mentioned i want Internet Tethering and Spirit is a untethered jailbreak so i need a downgrade, but recboot and irecovery doesnt work on windows 7, so i have a xp at home but would that work??? and also can i know whats the difference between DFU and Recovery mode??? can someone plz give me a simple way or give me a positive it'll work with Windows XP with irecovery and Recboot, and also has anyone tested irecovery and Recboot?

Sy.... etc.... do you know why the 1015 error pops up with windows 7 recovery mode?

[Sycamoira]

Hi Roy, I answered one of your other questions, but see you again and that you've got a sticky jailbreak situation on your hands.
No, Spirit doesn't support tethering right now.
DFU mode is a mode you can put iDevices in to load them with the firmware of your choosing-- in your case a previous version of iPhone OS 3. It means the phone is ready and waiting for the new OS, ideally. Recovery mode is a state where the phone can be restored to the os that is already installed-- like reinstalling the same version of Windows, for instance. iTunes will tell you that it has detected a device in recovery mode even if it is in DFU mode-- the difference is that the screen should be completely black as though your phone is powered off.
I personally have broken a recovery loop with Recboot (when irecovery wouldn't work.) This was on a Windows XP virtual machine running on my Macbook (don't ask, it was a complete mess.)
SO, for either of those utilities to work, you need to install the Libsub library-- you should have been prompted to do so when you installed irecover, but if you don't know what I'm talking about then that's a step you've missed, and you can catch up with this guide :http://www.maclife.com/article/howtos/downgrade_iphone_os_40#
If you installed the library file and are certain that you've followed all of the steps correctly, let me ask a question-- are you holding down shift when you click on the restore button on iTunes and it's offering 3.1.2 as an option? If so, you should try all this on XP when you get home.
Don't panic.