If you have Sonar version 2.0 or greater, you can go to Options - Control Surfaces and click the yellow + button on the screen to add a device (or if you have already done this step, you can double-click on US-428). Choose US-428 and the input and output port should be US-428 Control. If you do not have US-428 control as a selection, close out of this menu and go to Options - MIDI Devices and enable the US-428 Control ports on both input and output. Click OK and everything should work.