The untethered jailbreak of iOS 5.1.1 was released a few days ago and only some users have problems when using the 2.0 software Absinthe, being confronted with the error Could not connect to lockdown or Error Detecting currency (lockdown error
So do not worry, these errors are easily resolved:
Go to: Settings / General / Reset
Select "Reset All Settings"
Repeat the jailbreak 2.0.2 with Absinthe