no posting concerning problem,
not shure of the solution but there are a couple of threads with the title of U-Mix Control Pro,sound issues. the search tab will get you there, other than off the top of my head that you should use the dual stero mode to sort it out,,,, or you have issues with the i7 processor,,there is info on that as well, .
last thought is have you updated the firm ware for the controller
,dont have U-Mix Control Pro