Aside from that, Sn0wBreeze 2.9.5 also bring a fix of the location service issue when you are utilizing iPad baseband on iPhone 3GS, the issue found on the Sn0wBreeze older versions.
However this 2.9.5 doesn't support both A5X or A5 based device, as for that the developer recommending Absinthe.
“sn0wbreeze cannot be updated to work on A5(X) devices until a low level exploit in DFU or iBoot is found and made public.”
Download Sn0wBreeze 2.9.5 for Windows.
Now you can untethered jailbreak iOS 5.1.1 using Sn0wBreeze 2.9.5.