happy 4th of July from Ireland! I've been using my 3G iPad for a few days without a sim but purchased a micro sim yesterday pre pay data but for the life of me can't connect to the 3G network and keep getting a PDP authentication error (what ever that is). I was using my iPhone in the same area without a problem. I have registered the sim and my online account is showing credit. So far I have Restarted the iPad with sim in Restarted iPad with sim out and reinserted the sim Reset the network settings I am on the O2 network but have googled this error and it has happened to At&t customers so thought I would post here.