Just thought id share my experience with this to help others out
I updated to iOS 5.1.1 and restored the content on my phone using a back up i made, i then attempted the Absinthe Jailbreak and it said in the end "Something has gone wrong restoring iphone"
Next i thought id reset my iPhone to a brand new iPhone by wiping all settings and content off the iPhone, basically going into the General Tab of settings and selecting "Reset All" after doing this i attempted the Jailbreak again, same problem.
I decided to restore my iPhone again and reinstalled iOS 5.1.1, after install i set up my iPhone as a brand new iPhone, by going through "Enable location services" and the other steps till my phone was on the home springboard, i attempted the jailbreak and got the same problem for a third time.
Finally i decided to restore my iPhone AGAIN and this time once it had completed i DID NOT touch it, not even go through the steps, so basically the phone still had the setup screen displayed, e.g the "Enable location services" screen, i then attempted the jailbreak and SUCCESS, so if anyone incurs this problem of it not working try doing a fresh restore and not touching the iPhone
Hope i helped