iTunes 8 has been available since Tuesday and Apple is taking advantage of this software update to add a little grain of salt in order to prevent it jailbreak of your iPhone V1 or 3G.
iTunes 8 is, indeed, now capable to check if the firmware of your iPhone has just been unlocked or not. [If your iPhone has already been unlocked before, no problem!]
All this in order to put sticks in the wheels software like PwnageTool.
Faced with this new difficulty, the Dev team didn’t seem to have dropped the matter at all and have already developed a patch which allows pass besides this security.
This patch can be used on Mac, but Dev is already planning to work on a Windows compatible version, which should arrive shortly.
In the meantime, if you want to jailbreak your iPhone and if you're on Windows, stay or downgrade to iTunes 7.7.
We discuss it on the forum.
[Engadget | The Dev Team Blog]