in Gig Performer, Kontakt/Scarbee Jbass +slap bas is freezing/crashing app

EvenSteven

on a mac mini, using Gig Performer 5 and kontakt 8.

i'm using an instance with 2 instruments:

scarbee Rickenbacker velocity range 0-100

scarbee jay bass (slap) velocity range 100-127

CPU usage stays under 27%

1. setting the upper velocity range on the rickenbacker isn't stopping it from playing
2. while playing keys and keybassing, sometimes the system freezes. it's often enough for me to worry about using scarbee live.

thoughts, suggestions?