If you’re a fan of jailbreaking your iPhone or iPod Touch be careful about updating to Apple’s latest 10.5.6 release of OS X. According to many reports, as well as the iPhone Dev Team, the update changes something at the system level that affects the DFU mode when flashing the firmware with the pwnage software. There are apparently a few ways around this which require replacing some of the framework files for the system, I wouldn’t recommend these. The iPhone dev team is working on figuring out the problem, which they don’t think is intentional. So hopefully in a few days they will figure out how to get around this. I’m already jailbroken on firmware 2.2 so I haven’t needed to try this out, anyone else having problems?

iPhone Dev Blog