This works for it might work for u 3.1 users!

[swoosh0217]

PAY ATTENTION AND READ CAREFULLY!

After doing this tutorial, scroll down to the bottom right and follow all Jailbreak and unlocking instructions. My iPhone is now Jailbreak and Unlock with 3.1 Firmware. Im very lucky that I got one of those 5.08 Bootloader!


http://www.redmondpie.com/downgrade-iphone-3g-firmware-3.1-baseband-05.11.07-to-04.26.08/

 

[dhlizard]

PAY ATTENTION AND READ CAREFULLY!

After doing this tutorial, scroll down to the bottom right and follow all Jailbreak and unlocking instructions. My iPhone is now Jailbreak and Unlock with 3.1 Firmwares. Im very lucky that I got one of those 5.08 Bootloader!


http://www.redmondpie.com/downgrade-iphone-3g-firmware-3.1-baseband-05.11.07-to-04.26.08/

As you said, it woks for 5.08 bootloader only !