Sound cuts with DDJ-T1

I'm using DDJ-T1 with Traktor Pro 2 (version 2.6.8) on my macbook pro. In the last couple of weeks i've had a problem with music stopping while playing tracks. Music stops for 3-4 seconds and then plays normally again. During my sets (lasts 5-6 hours) it happens usually 2-4 times. Any ideas - is it more hardware or software problem? Right now i have no ideas, where to start looking for a solution. Thanks!