Help with unlocking

Your phone has been activated previously. Here is why.

1. It has the baseband of 05.15 which is for firmware with 4.2.1.
2. I believe because he/she saw that the phone is operated too slow on 4.2.1, he/she downgrade it to 3.1.3 which is best for 3G.
3. Your phone has bootloader of 06.04. So, you can't use fuzzyband to downgrade it baseband at all.
4. Since you have 3.1.3, when you use the latest redsn0w, it will not recognize the firmware. However, if you use the old redsn0w, it will not have the option to "install Ipad baseband" for you to unlock.

So, depending what you need to do. There are options for you.

1. If you just want to jailbreak it. You can do that from your phone Safari. Just type in jailbreakme.com and follow its instruction, you will jailbreak your phone at no time.

2. If you want to unlock it, then first you will have to upgrade your phone to the latest firmware which is 4.2.1, then you can use redsn0w 0.9.6rc16 - 0.9.6rc18 or so to jailbreak it as well as installing an ipad baseband. However, before you install an ipad baseband, please read the following post.

http://blog.iphone-dev.org/post/1718400992/ultra-recycle