I have the VX4400 and live in a 1x area. However, for some weird reason in the parking lot of my work building, where the 1x signal is pretty strong, is starts switching back and forth between Analog and 1x usually every 10-15 seconds. I have no idea why because each time it switches back to 1x it has a nearly full signal. So my question - is there a way to limit it to only 1x and digital? My old phone used to have an option to disable analog, but I can't seem to find it on this one. Thanks!