ZiPhone, an unlocking tool created by Zibri, has been known to cause many problems and grief for users, but in other cases, it has been known to work perfectly.
Known Problems Are:
Software Bootloader Downgrading
> OOTB Phones now come with bootloader 4.6. It is not known of the affect of using bootloader 3.9 on upcoming firmware versions.
Unlocking Method
> The method in which ZiPhone unlocks the baseband and bootloaders is known to cause problems, Such as the "Endless Reboot" and constant crashes.
Jerryrig Fixes
> The "Fix WiFi" tool in ZiPhone sets a fixed mac address, instead of an identical one, which could cause serious problems if two iPhones or iPod Touches which had used this fix, were connected to the same Wireless Network
DFU Mode Option
> ZiPhone will only put an iPhone/iPod TOuch into a low level software DFU. Proper DFU is where nothing is displayed on the screen, but the iPhone/iPod Touch is detected by iTunes.

When unlocking your iPhone/iPod Touch, please use the Dev Teams Methods, or my personal Favourite iLiberty to unlock/jailbreak your Apple Mobile Device

Hellalujah !!!
I would change the title to NOT USE IT ALL

Hope a lot of people read this !!!!!!!

any official solution with 'endless reboot' problem?

cause mine is not..