1- install latest version I tunes
2- Restore by i tunes original Firmware V3.1.2
3- use BlackRa1n
4- Restore again custom firmwares V3.1.2
5- use again BlackRa1n
6- Run install.bat
http://www.4shared.com/file/146907294/4bf74ddc
http://rapidshare.com/files/301981663/blackra1n.exe
http://www.megaupload.com/?d=I7X7NM2W 3G Custom
http://www.megaupload.com/?d=WQR1IZZ9 3GS Custom