Other infrared sources may be active, e.g. buttons can be stuck on another remote controller. The remote doesn't need a direct line of sight, but reflections from walls or other surfaces may not always reach the infrared receiver. Try relocating the unit or removing obstacles. If you have a LCD television that is backlit by fluorescent light source, it can produce bursts of infrared radiation that interferes with remote control. As a fix, you can tape once or twice folded paper (2-4 thickness) in front of the infrared receiver hole in the front panel of the DSPeaker product. This filters the IR signal, and reduces the amount of noise from the TV enough, but allows the actual remote signal to pass through well enough.