helpviewer and a wxpython application crash

[accolades]

I haven't run into your situation, or tested the concept, but my first
guess would be that the helpbook is throwing an exception of some sort.
You might try turning on the debugging options, or try using the
command line interpreter to launch the helpbook. When you close it, you
should be able to see what exception is being thrown (or what other
error might be cropping up) and handle it appropriately in your code...

Not sure if that helps, but I hope so :)
Tim