Download redsnow 0.9.11b1 for iOS 5.1.1 to 5.0.1 downgrade for A5 Devices
Well Dev Team has already released Redsnow 0.9.11b1 for downgrade iOS 5.1.1 to iOS 5.1 and olders for A5 devices, which includes The New iPad as well. And it is particularly released to give feature to redsnow for downgrading via Restore method. Now you do not have to manually change the note file for editing Host name. But one is pretty much clear that if you depends on unofficial unlock via Ultrasnow, do not update to iOS 5.1.1 with A5 device.
but so far here are the updated links for the Redsnow update.
if you need to have proper guidelines for Downgrade A5 to older firmware like IOS 5.0.1 or iOS 5.1 or ioS 5.0 you can follow the official Dev Team blog