I doubt it. You are talking about being plugged in to the USB port on the PC, right? The icon in your screenshot seems to indicate that. It looks like the PC thinks the device has been disconnected and cut off the power until a new power negotiation takes place but that will not happen because the device still thinks it is connected. Have you tried telling the phone to switch to either mass storage or PC Suite mode? That should keep the connection alive. (Caveat: I do not know how GPRS modem works.)