mac sound output dropping after using traktor audio 2

Hey guys,

i own a mac pro 10.8.3 and also a tractor audio 2. I barely used connect these two before until i got a new pair of krk's which i connect to my laptop everyday now.

now whenever i connect the audio 2 to the laptop the audio of my laptop automatically get all played thru my monitors. also every time my work is over, i just go over and switch the monitors off and then remove the audio 2 chord from my laptop. since theres no eject option.

off late ive started noticing, that when i use m laptop speaker and audio is playing the sound drops out for 1-2 seconds and comes back. this happens quite often. also i feel the max volume of the laptop is reduced. safari stopped playing audio from youtube for a sometime and came back again. Whats the issue?