I'm attempting to jailbreak my iPhone 3G on a Mac but am having no luck. When I get to the part when the phone goes into DFU mode my screen turns white and remains that way. The quickpwn app continues on as if there is no problem all the way through. The screen remains white for apprx. 10 minutes then shuts off. And my phone is back to normal after powering it on but not jailbroken. I've read of other people having this problem in other forums but I haven't found a solution. Can anyone help?