Logic X audiodropout with MOTU 828 X

Machine: Macbook Pro 2,5 GHz i7, 16GB Ram, 512Gb SSD. Oktober 2014

Software LOGIC X

System: Mavericks, Yosemite

Hardware: MOTU 828 X, MOTU 8pre USB

Kabel: Thunderbolt, USB

Hi, I'm experiencing audio dropout when running the setup listed above. The dropout is not reproducible - sometimes the system runs for hours without a single dropout - then again sometimes I get dropout every 5 seconds.

- before replacing my 2009 Macbook with the 2014 Macbook I connected the same MOTU hardware via USB running OS X 10.8 and everything was perfect.

- Then I upgraded to OSX 10.9 and audio dropout started happing.

- I changed to the brand-new 2014 Macbook. Same problem

- I upgraded the new Macbook to OS X 10,10. Same problem

- On the MOTU Interfaces the firmware is the latest version 1.04 and the audio driver is the latest version dating 17. October 2014

- Even with older drivers and firmware always the same problem.

- No fusion drive on my Mac

- very occasionally the dropout problem even occurs when using the the onboard sound hardware while using Logic X

Since the audio dropout problem occurred on 2 different MacBooks and only started when I upgraded from OS X 10.8 to 10.9 I guess it is a:

1. MOTU driver / firmware problem

2. LOGIC X problem

3. OSX problem

Since I need my Mac for professional audio work I really need a solution to this problem. Even MOTU / Germany has no clue.