Exploit Failed... Iphone 4 CDMA Please Help

Morning. I have been trying to Jailbreak my Iphone 4 CDMA Verizon for about a day now. I did my buddies phone which is identical to mine, and it worked. But when I do mine, it recognizes it is DFU mode, and proceeds to start the process. Runs Limera1n, and then it says Exploit Failed. and Stops.

Can anyone assist me in this as to what im doing wrong or how I go about to fix this problem.

Thanks Much