Midi config issue Sonar X1 w. Axiom 61

Here is something on page 32 of the manual that came with your Axiom 61 that might help.

"4.1 MIDI Out from USB Function
MIDI Out from USB can be used to switch the source of the MIDI data seen at the MIDI Out port of your Axiom.   
On initial power up, MIDI Out from USB mode is off.  This means that as you play your Axiom, MIDI data will be sent to the MIDI Out port.  

If you turn MIDI Out From USB mode on, playing your Axiom will no longer send data to the MIDI Out port.  The data is instead streamed from the computer.  So, as long as you have selected your Axiom as the active output port in your computer’s sequencer, this is the data that will be sent the MIDI Out port.

For example, if you want to control a sound module from your Axiom, you should ensure MIDI Out from USB remains off. If you want the sound module to play data streamed from your computer however, then you should turn MIDI Out from USB on and ensure that the output port for your Axiom is selected as the computer’s MIDI output device (this is done in your computer software)."

So, I would change the USB Midi mode before using it with Sonar. Once the Midi Out is enabled for streaming from the computer, it might be recognized as a Midi Output device.