i have traktor scratch installed on my computer and have my xone 42 connected to a hercules mk2 which of course is going into my comp

i have channels 1 and 4 hooked up but....
my problem is when im playing a track through channel one it plays through channel 4 as well ( almost like the sound is split) and when im just playing channel 4 its fine

i tried it out through virtual dj (ya i know..) and it works fine

any ideas? thanks