When a song is playing on deck A in Traktor, the output in mainstage and logic are muted to the beat of the song playing (in traktor)

I'm trying to play the ultrabeat drum patterns out of Mainstage into Deck D as an audio through in Traktor and it works fine until I play a song on Deck A...

Why is this? Any ideas? Until I can get it to stop doing that it is impossible to use the two programs together.

Thanks for you're help,
Uncle DJ