I had to get my 4G SIM card replaced recently. Before I had to get it replaced, I could run S.U. ANYTIME and it would tell me that if there was/was not an update for my Thunderbolt. Now with the new SIM card, if I run it, it won't tell me if there is or is not an update as it did before. I am thinking either the phone is screwed up or it's the SIM card. How can I tell which one is messed up??