I received this as a gift about four months ago, worked excellent until about a week ago.  Now, all it does is chime.  I've tried resetting the network, cleaning the brushes, cleaning the wheels, cleaning the filter, everything.  The only help I could find was to make sure the dock is the one that came with the robot, well, I only have one dock and it came with the robot.  I am beyond frustrated with this product.  I press the 'clean' button, it goes for maybe 6 inches and stops, I press the 'dock' button and it gives me an error message and goes back to chiming every 10 seconds.  It even chimes when it's charging.