MAudio keyrig 49 and Sonar Home Studio

Hi, another newbie signing in! I've been using Sonar Home 6 for a few years with only minor difficulties.  That is because until now, I've only been tracking stuff with a Line6 UX2 interface + ampfarm software, and an alesis drum machine.  Guitars, basses, vocals, and the occasional imported sample; no problem for the midi illiterate.  Now I've purchased my first keyboard controller, the entry-level MAudio Keyrig 49.  It's a USB unit that works fine as a standalone keyboard, but won't work in Sonar.  It shows up under midi input sources in Sonar, but Sonar won't let it become the midi input source.  I check the box and close the window and nothing happens.  I go back to the window and the box has unchecked itself.
 
Can someone please tell me what I'm doing wrong?  Any and all help will be greatly appreciated!