[Chewbacca]

I get this as well, ocassionally, while editing conversations and scripts. I read somewhere that using a system monitor can warn of a sudden spike in memeory usage, giving one time to save and shut-down the toolset. I haven't tried that.

I personally have decreased this from occuring by loading the script or conversation file from the left menu bar instead of through object's properties menu. The toolset seems to work more efficiently this way.