I have a device, namely a Davis Vantage Pro2 Weather Station Console, attached to the second USB port on a laptop; the first port is used by a mouse.  Occasionally the port on which the console is visible changes from /dev/ttyUSB0 to /dev/ttyUSB1.  I haven't noticed any reason for this, in particular no change in physical connections; it just happens when it happens.  This prevents some software which handles the console from operating, since it's expecting to find the console on /dev/ttyUSB0.

Has anyone else noticed anything similar?  Any idea what's happening?

Thanks - jon