Absinthe 2.0 was the first tool released to jailbreak the iOS 5.1.1 on Apple devices, but as sometimes happen, first releases always reveal bugs.
Here is the Absinthe 2.0.1 released to fix a hang in certain situations. @pinskeks tweeted:
#Absinthe 2.0.1 is out fixing a hang that could occur in certain situations. Get it from greenpois0n.com
— Nikias Bassen (@pimskeks) May 25, 2012