I recently received a refurbished Rezound from Verizon as a replacement, and have been experiencing a few bugs. When I turn the phone on, I will occasionally get an error message saying that the device needs a SIM card to work, and to power down the device. After probably less than a minute, that error message goes away, and the phone finishes booting up and connects to 1X. I normally have the mobile network off, and when I turn it on, I sometimes find there to be a very long delay until the 4G symbol shows up in the status bar at the top. I will sometimes toggle it off and back on if the delay gets too long, and that will sometimes work. Other times I may do that a couple times before it will come up in 4G. After doing a reset to stock on my old phone, I found I had to take the battery and SIM card out, and put them back in, before I could connect to 4G. It also had the long delay time in 4G turning on, even before the reset, (which I did for another reason.) Does all this sound like a SIM card problem? I still have my old SIM card in this refurb, and it would do similar things in the old handset, except for that error message on booting up. Thanks!