If your Device is the VL600 Modem using VZAccess Manager and you have a problem with a sim not found or sim error, here's the help that phone support gave me. My problem was resolved.
I am using Windows XP, SP3 with Media Center. This may or may not apply to other system types.
Disconnect the VL600 device. Go to Start, Programs find "Media Center" and click it. It's an Icon under "All Programs". If you have not already setup Media Center. Go through the steps to complete set-up. Once set-up, right click anywhere within Media Center to bring up "Settings" option and click it. Then click "Messenger and Call ID" option. Select "None" and "Save". Close Media Center. Open VZAccess Manager if it's not already open. Now connect your device. It should now be fine.