Qt Assistant as Custom Help Viewer - Home button doesn't work?

Question

The <homePage> tag in my .qhcp file doesn't appear to work. Sometimes it seems to set the page I specify in that tag to be the value in Edit..Preferences..Options..Homepage; sometimes not. Either way, clicking the Home button does not work. Sometimes it does nothing, sometimes it says the page could not be found - and gives what looks to me to be a perfectly valid path.

Any ideas? Or worst case, is there a way to get the viewer to not show the Home button?