Sometimes when I switch key lock on in traktor pro my sound becomes very distorted. I have no clue why (I have tried adjusting the latency settings with no luck). When I turn it off it returns to normal or it after a while it will sound normal by itself.
It may have to do with the latency in your audio settings page. Try going up a little and see if that does anything. Also, try using different latencies with different bitrate outputs. I run mine at 96000 with a latency around 13 and will rarely hit a problem.
.. but you won’t be able to burn it to cd at that rate, and others cards that don’t go up to 96k won’t be able to play it back like that (iirc). i don’t think itunes will even accept a bitrate that high.