Impact Soundworks fixed some bugs in their Kontakt library, Super Audio Cart.  Specifically one I was having with Kontakt dying when using a bunch of fast arps (the "Crunchy In Milk" preset).  This new update fixes that problem and I gather some other things as well.  If you have this you might want to get the update. This KvR post is pretty much the only source for the new files:
 
http://www.kvraudio.com/forum/viewtopic.php?f=176&t=484044
 
Note, that reloading an old SONAR project will also reload the saved/old instrument/script.  So you have to remove and replace it inside Kontakt or you'll still see the problem (in my case after playing a bunch of MIDI notes Kontakt starts spewing script errors and eventually overloads the CPU and kills the audio engine).