The Netscape navigator is launched via a script /usr/bin/netscape. This script attempts to set the users homepage to /usr/doc/HTML/index.html automatically, unless the user disabled displaying the homepage at startup. It does so by looking into the users preferences.js file. However, the detection is broken, because line 166 reads if grep "\"browser.startup.homepage\"" \ and not if grep "\"browser.startup.page\"" \ as it ought to.
Huh? Looking in preferences.js here, the line is 'browser.startup.homepage'.
Oh, I see. browser.startup.page is 'display blank page/homepage/last page', while .homepage is the actual homepage. If you just set the home page to *something*, then setting it to 'display blank page' should work OK with the script as is. I'll look at fixing this...
This should be fixed in the current netscape build (-4 or so) that will be available in the next rawhide release.