Recently Apple releases 10.5.6 update which includes alot of performance improvements bla bla bla and also breaks the ability of your mac to manage a device on DFU mode. This making technically imposible for jailbreakes and curious developers to work the the iPhone and the iPod Touch.

I'm sure you've heard of the infamous Automator script that is running wild on the internet. Well, I don't know if it's me or that thing just doesn't work on Unibody Macbooks Pro's :( Obviously if you are here you are one of that poor guys with a brand new shiny Unibody Macbook Pro like me and you are having issues jailbreaking your iPhone, don't worry here's a fix for you my old camarade.

The problem starts with the new USB drivers bundled on 10.5.6 so the first thing you'll have to do is go get a copy of the IOUSBFamily.kext from a 10.5.5 machine, I'll wait here... If you came back with your hands empty you can download a copy of the driver from here:

http://www.mediafire.com/?sharekey=c27475908080a4e4d2db6fb9a8902bda

After that we are going to have to do some man work with the Terminal.app you can find it on /Applications/Utilitys/Terminal.app and here we go:

First unzip the file to some place you know where it is like your home folder

Second type this down

type sudo -s and enter your password, this will put you into root mode

Backup your IOUSBFamily.kext

cp -R /System/Library/Extensions/IOUSBFamily.kext ~/

Delete the old one

rm -r /System/Library/Extensions/IOUSBFamily.kext

Move in the new file

mv /Users/User/Downloads/IOUSBFamily.kext /System/Library/Extensions

Change the permission and the ownership of the file

sudo chmod -R 755 /System/Library/Extensions/IOUSBFamily.kext
sudo chown -R root:wheel /System/Library/Extensions/IOUSBFamily.kext

Now delete your old Kext cache, WARNING DON'T DELETE DE EXTENSIONS FOLDER DELETE DE .mkext

rm /System/Library/Extensions.mkext

Wait a few moments and reboot your machine

Now you are ready to go, happy jailbreaking

Hope this works for you as it worked for me