MacBook, Audio 8 and Traktor Scratch Pro Help

Hi All

been searching for almost two weeks in case the post has been addressed but no luck. pls help.

I strated out with Traktor Pro and my Macbook with Behringer MS40 monitors and BCD3000 Behringer mixer. worked well until one day i decided to use my headphones via Itunes, thus i change the sound output. since then when i select BCD3000 as an output device, Apple reckons it does not have an output device. i could only get feedback from my headphones bt not monitors.

After much stress and searching, i changed my output settings on Traktor where i used the recording setting and selected the speakers from the the list. worked well.

Now i have an audio 8, Traktor Scratch Pro and no sound again. The software works with the turntables etc, but no sound. i have tried to change the output settings to no avail,
Apple does pick up the Audio 8 but says again that it has no input or outpu.

i have been searching now for almost two months with no help.... anyone???