traktor et rmx2 audio issue

i have traktor scratch pro and a rmx2 and if i have traktor open and connect the rmx2 it wont connect to the audio.  it only seems to connect when the rmx2 is switched on 1st and then i connect to traktor.  is there any way around this??

several of us use the same laptop to have a mix and its annoying when you change over and have to shut traktor down just to connect