p0sixspwn reboot problem

Recently i jailbrake my iPod 4g with ios 6.1.6 with redsnow under this http://www.iphonehacks.com/2014/03/jailbreak-ios-6-1-6-redsn0w-p0sixspwn.html instruction. The jailbreak went perfectly. It says i can untether my iPod using p0sixspwn. So i give it a try.

After i reboot the device (without redsnow of course, because i think it'll work perfectly), my device's screen starting to crash. The "screen" that i can interact with is getting smaller and it only takes 1/4 part of the real screen. I had to reboot it again and enter safe mode, because no matter what metode i use (force-to-boot metode, reboot it using redsnow) to enter the jailbreak mode it'll crash the screen. And btw, i can't remove p0sixspwn.

Any solution i can try?? I will happy to provide screencaps if you guys need one (or more). I already looking for this problem solution, or at least people who has same problem with me, but i got nothing. Thanx :)
And sorry for my bad english.