Reply to Problem - Cue Point Buzzing

I am having the following problemn with my S4 software - I am getting an intense buzzing sound whenever I set a cue point on a track. So far I've only heard it through the headphones (I was playing out, and when I heard that horrible buzzing I knew I couldn't even try to raise the volume on that channel).

Its happened with 2 different S4 controllers, same lappy (I brought my MBP to a party and hooked it up to my friend's S4 and it happened the same way), and it only happens when I set a cue point (not with simply playing a track, looping, effects or samples).

Thoughts?