Rekordbox dj 4.4 and 4.5: potential stuttering/hiccups during a 4-5h set

Hey Pulse, people at Pioneer.
Ok, first things first, specs of my Macbook Pro:
2,5Ghz i5 processor
8Gb Ram
500Gb hdd with about 200Gb of music
Timemachine is OFF
Wifi/bluetooth always OFF
Energy settings to the max
Rekordbox is always the only software that is running when dj-ing.
No other apps in the background.

But stil, I keep getting annoyed by potential "stuttering" during my
+4h sets. May happen 2-3 times during my set. And the stuttering is there for 2-3sec. Not very long, but long enough for the crowd to "boooh" at you as a dj...

At the moment, I'm trying to recreate this stuttering in my livingroom.
I have my Macbook Pro with Rekordbox dj and a Traktor 2 Soundcard with a headphone plugged in. No other hardware!!
I'm using the autoload function and let it play for a few hours while I'm doing other stuff
And still, with only the soundcard connected, potential stuttering and hiccups of the music...
Any ideas????