had a similar thing...although the quitting wasn't consistant -it quit a fair old bit though, also when accessed through the 'help' menu. With me it would also very often simply load a blank helpviewer window. This was in10.3.2 and 10.3.3. I never figured out what was causing it, and eventually gave up. It may be coincidence, but I checked again after a while, having meanwhile upgraded to 10.3.4, and it all seems to work, except for a vaguely annoying trait it has of writing the text off the right side of the window, no matter how I resize it.
I should mention that I'm using a 12"pb, and have almost exactly no idea what I'm doing most of the time, since it's my first mac... (I like it though

)