jailbroken iPad 2 wont start after installing spirit.

As above my iPad 2 5.0.1 won't boot up. I was going to restore through iTunes but then it said it will update software to 5.1.
Is there a way of restoring and not updating firmware as 5.1 is not untethered jailbreak.
I've tried pressing shift and restore but get the error message.
Hopefully someone can help me