Okay, thanks for the update. I'll have to mess around with it some more and see what I can figure out. It seems like it almost definitely has to be some sort of memory/instability issue since it's random like that. I appreciate your patience in working through issues like this, and hopefully it doesn't hold you up too much in the meantime.
I've had to rewrite a lot of code due to the latest Voxel Editor changes, but I think it will be worth it, and it's forced me to clean up some things along the way. :)