Make sure that the UA-5 is the selected output device (under options, settings, soundcard)
Try setting the recording software to 'monitor' the output (check box on the bottom of the box that pops up when you hit the 'record' button).
I think that should route the digital signal back into the UA-5. You might need to use the ASIO drivers. Even if they're not needed, they would probably place less stress (i.e. bandwidth requirements) on the USB connection.