What type of bulbs dim to lowest setting?
Have you adjusted the low-end trim? There is a PDF which they class as "advanced" instructions that describes the procedure on Page 25. 


Hold On button for 6 seconds, until LED (on dimmer) starts to flash.
Hold Down button until lamp turns off or starts to flash.
Tap Up button until lamp is not flashing and is stable (or is as bright
as you want the lowest dim to be.)
Hold Off button until the LED (on dimmer) stops flashing.