getting in to dfu with broken home button on mac

i have a broken home button on my iphone 2g with the latest firmware and need to get in to dfu i tried on a pc with a tool that i downloaded but it just sent the phone into restore and i need to put on a pwned firmware. so if any one can get me in to dfu would be cool

ps i tried in restore mode and got error 21

thanks for the help

Have you tried using ziphone 3.0?
it has a dfu mode that'll do it for you