We've confirmed there is a bug in authentication affecting some Picpic Social 1.x users. The bug occurs when you enter the PC password onto the iPad. Once the password has been entered, the Picpic Social application says "authenticating" but it does not move beyond this screen.
This bug occurs due to a setting in some iPads that we have not yet pinpointed. The only known fix is to backup your iPad and perform a factory reset.
We are still working on a permanent solution and will update everyone when the fix has been found.