I jailbroke my ipad with redsn0w on 4.2.1 and got it working fine. I installed infinidock and it rebooted the ipad but unfortunately it gets stuck at the apple logo. This means I had to boot into recovery mode and restore the ipad as I wouldn't get it to turn off so I could do a tethered boot. Just thought I would let you guys know it seems like infinidock is a no go until its untethered...either that or there is some other way to shut off the ipad that I am not aware of