MuscleNerd has just tweeted moments ago which addresses an issue with iPhone 3GS users with an old bootrom. Apparently the old-bootrom 3GS users who are luck enough to enjoy the untethered experience are facing problems when doing the jailbreak with the previous RedSnow version, says Wahaab JB of Chip Hazard.
This problem has been fixed in their new version for RedSnow 0.9.9b9d which is recommended by the renowned hacker in order to successfully jailbreak the device. After downloading and installing the jailbreak, then proceed with the UltraSnow unlocking procedure with your iPhone.
The procedure is simple, after downloading the latest Rednow version from the direct links given below launch the tool and goto Extras->IPSW and manually select the 5.0.1 IPSW, then go back and Jailbreak it again. This version doesn’t provide the untethered jailbreak for any other device at the moment, that jailbreak will be provided at the moment by just pod2g in the coming days.
Following are the links for download and use UltraSnow after jailbreaking the device from this tool.