[DoerrFan]

Update #2:
Three official options from dev team

1. Replace the following plugin kexts from within IOUSBFamily.kext with the ones from 10.5.5 and then rebuild kextcache.
/System/Library/Extensions/IOUSBFamily.kext/Contents/PlugIns/AppleUSBHub.kext
/System/Library/Extensions/IOUSBFamily.kext/Contents/PlugIns/IOUSBCompositeDriver.kext
2. Use a USB hub in-between the DFU device and the Mac and insert/reinsert the iPhone’s USB cable.
3. Use a PwnageTool created .ipsw on Windows.

Cash Update: So I've been playing with this for a few hours now. 10.5.6 will not let you use DFU mode to restore custom firmware to a phone that IS NOT already pwnd. Replacing MobileDevice.framework with the previous version does not seem to matter either -- have not tried replacing the framework and downgrading iTunes or replacing other frameworks/haven't ahd time to dig in to the drivers and replace yet. A USB hub will work just fine with no issues at all to pwn on 10.5.6 with the latest iTunes. Had zero issues with my powered USB hub. Tired now and not interested in restoring anymore tonight so some updates from our members. One report says that QuickPwn works fine. If your iPhone is ALREADY pwnd and you need to restore with a custom firmware it has been reported to work. Windows users report no issues at all (of course) this is just a mac thing with the 10.5.6 update.

According to some iPhone news sites, the latest Mac OS X release (10.5.6) disables the use of DFU mode. This can be bypassed by plugging your iPhone into a USB hub. The Dev Team has been notified on this and a fix will probably be here soon. For now, do not update to 10.5.6 if you want to jailbreak your device unless you absolutely have to...or have a spare USB hub.

Basically it scattered reports are claiming that everything will work properly if you are connected to a USB hub instead of directly to the computer. The idea behind this is that the drivers for the USB hub will still allow you to connect in DFU and do your thing where the updated drivers in 10.5.6 when you connect directly to the computer would be fubared. What also would probably work is if you took the 10.5.5 [script]drivers[/script] framework and stuck it on 10.5.6.

Here at MMi we will confirm things sometime tonight. If you have tested this out yourself post up!

Oh and thanks to strchris for making his first post on our forums earlier today to warn the rest of us jailbreakers of the potential problem.

Via [iPhoneAlley and TUAW]

[cricketlang]

good to know. even though i dont work with macs i will keep this info on file. the approach seems similar to the one with the new macbooks. dev team will rise about all

[Poseidon79]

Uuuuuh... this is gonna sound dumb, but what's a USB "hub" and why does this bypass the issue?

[cricketlang]

a usb hub is like one of those things you plug into a laptop or computer to get more usb ports......like this:

[Je5]

Ok so how does this not affect the phone it is using a USB isnt it...?

[cricketlang]

its probably something to do with drivers. the hub uses its own drivers usually as it packs 4 ports into one so it has to do something special. just use a hub....its simple

[tattoojack]

thank god i just got an externally powerd hub!
because the one listed above will not work for iphones.
not enough power to charge.

[cricketlang]

^^^^yeah i was just showing an example of what a hub was. thats all. it was the first one that showed up on google. hahahahaha

[jiniej]

Uuuuuh... this is gonna sound dumb, but what's a USB "hub" and why does this bypass the issue?

Heh heh heh
That made me chuckle.

And yeah, using the hub probably has something to do with the drivers, like cricket lang said. Just reiterating...

[toothy17]

Now The Next Thing We Will Have To Worry About Is Apple Getting iTunes To Disable It But Thats Y We Love The Dev Team To Fix These Encounters

[Chase817]

Oops. I could've used that warning before I upgraded 5 MINUTES AGO.

[StevenSimpson]

Originally Posted by Chase817

Oops. I could've used that warning before I upgraded 5 MINUTES AGO.

me too!!

Oh well...I have a USB hub around here somewhere...

[ddfilms]

I am on 10.5.6 and i just jailbroke and unlocked an iPhone today with quickpwn, DFU worked fine.
FYI

[StevenSimpson]

Originally Posted by ddfilms

I am on 10.5.6 and i just jailbroke and unlocked an iPhone today with quickpwn, DFU worked fine.
FYI

What hardware are you running?

[jackyk]

I'm successfully restoring with a custom 2.2 ISPW on 10.5.6. Instead of putting the iPhone into DFU, I put it into regular recovery mode.

When in this mode on the iPhone the iTunes logo and the USB cable is shown (Apple default), or "Steve" (Standard Pwnage) or your custom recovery logo.
1. Disconnect iPhone from your PC/Mac if not done already.
2. Hold Power/Sleep until the red slider shows up, slide to shut the iPhone down. If this aint work hold Power/Sleep and Home until the iPhone shuts down. Put it aside.
3. Start iTunes on your PC/Mac and make sure to have the latest version.
4. On the iPhone press Home button and keep holding it while connecting the iPhone to your PC/Mac.
5. iTunes will detect an iPhone in recovery mode, the iPhone shown the recovery logo.