This is a strange problem that I have encountered. I have a customer's phone that is stuck in a bootloop. The phone boots up, then about 10 seconds after seeing the unlock screen, it reboots. Here's the kicker: It only happens with a SIMple Mobile SIM installed. I have done a data wipe / cache wipe / factory reset. I even installed Arhtard's Deoxed rom, with no issues whatsoever. Without the SM SIM, it works beautifully, it even works with a known-bad T-Mobile SIM... just not my known good SIMple Mobile SIM. It makes no sense whatsoever. This is a SIM card that I use in my personal Android HD2. I use it to test many of the other phones here in my store. I called SIMple Mobile and did a SIM swap, however, the new SIM did the same thing. It doesn't bootloop with SIMple SIMs that are not active. I do not have an active T-Mobile SIM to test it.