I am running Windows Vista
Iphone 3g 2.0.2 firmware
I just bought this phone, still reading through things trying to sort this out on my own but information seems a bit limited in regards to jailbreaking the newest phone / software.
I downloaded quickpwn again and it was different, I believe it was updated some. I got the jailbreak to work and so far things are working well enough. Installer wasn't working last night but it updated today and seems to be working very well, customize works fine but I can't change wallpapers or audio, it has trouble copying only those file types for some reason. Cydia works great and was updated again today and seems to work better.
Looks like things are coming together for the 2.0.2 firmware and the 3g iphone. Other than the issues here an there it has made for an entirely new experience with my beloved iphone.
one thing i did that might help is hook ur iphone/ipod touch to itunes and put ur device in dfu mode b4 using quickpwn. after device is in dfu mode go thru the steps of quickpwn and u should be ok, gl!
Remember that the phone must be OFF before you start the quickpwn process. I don't know if this helps the error but the software will tell you to do this anyhow. Might as well just start out that way in the first place.
Again, if you are having crashing errors then head over to quickpwn's site and download the gui again, it is an updated version that works.