RedSn0w Updated to Fix Issue on OS X 10.5.x
The iPhone Dev-Team has released updated RedSn0w 0.9.10b6b for Mac OS that fixes an issue for those on Mac OS X 10.5.x or earlier.
Update #1b: The OS X version of redsn0w has been updated to fix an issue for those running OS X 10.5.x or earlier.
You can download the latest version of RedSn0w from here.
Our step-by-step tutorials for jailbreak iOS 5.1 using redsn0w 0.9.10b6 are here.