bouncing FLStudio Multi tracks??

hello,

im having problems bouncing FL tracks down in sonar.
when i open FLStudio multi in my DXi rack i get 16 stereo tracks open.
i then route my pads through FL track 1, drums through FL track 2, vocals through FL track 3 and so on. this all works fine.
but when i try to bounce any of these tracks down using, edit bounce to track,
i get a message saying, cannot complete request because the pins are not connected.
i use bounce to track all the time with soft synth and have never had a problem.
if anyone knows of a way around this it would be much appreciated.

cheers
mark.