So is this the phone or the network? I have a Bionic that loses data all the time, talking to verizon tech support I asked if the Nexus was having the same issues and she told me there where no known issues with dropped data. If I can't get the Bionic to work correctly they will send me another but if it still is an issue I will press to switch from Motorola.
Its the network. It's simply down in some areas. I don't know why it keeps crashing but that's what tech support told me.