I purchased two Droid 4's that day they came out from verizonwireless.com. I've had each of the previous Droids and thought it would be a simple switch. Upon receiving the phones, I got each setup and running and then moved my 16GB SD card from my current Droid 3 to the Droid 4 planning to format it in the Droid 4 to start with a fresh slate. When powering the phone one, it recognized the SD card and displayed the "Preparing SD Card" message. This message never goes away and the SD card never ends up being mounted. I had the same problem with the other Droid 4 with a new SD card. I've put the card back in the original phone and formated it and then swapped it to get the same results. I've formated the card on my PC and put in the phone and got the same results. I've formated the card to NTFS at which point the Droid 4 does recognize it as an unusable format, formats it, but then continues with the "Preparing SD Card" message. Fortunately the 16GB of built in memory has allowed me to continue to use the phone, but at some point I would like the SD cards working in each of these phones. Any suggestions? And yes, I have done a factory reset, soft reset and hard reset, none have made a difference.