another website. iphoneheat.com has customer firmware created with snowbreeze. it sounds like this is the only solution for me right now to upgrade to 4.0 and keep my jailbreak. I'm still on 3.1.2, jailbroken with blackra1n.
custom firmware could really mess up ur phone so it has to be a site you trust or a site others have used and had no problems. Do you have a Mac you can get pwnage tool and make your own firmware, if not PM me and we'll talk ;0) you can search on here I have been here awhile so I aint going anywhere.