I am very grateful to Ian Hutchinson for providing the following fix. (NOTE: This fix applies ONLY to version 6 and later of Netscape Navigator, and to Mozilla. In particular, it is not needed on versions of Netscape Navigator up to 4.)
In the file
fontEncoding.properties
(which is located in the directory
\Program Files\Netscape\Netscape\res\fonts
under the default installation of Netscape 7.0, and in
\Program Files\mozilla.org\Mozilla\res\fonts
under the default installation of Mozilla 1.0), change the line
encoding.symbol.ttf = Adobe-Symbol-Encoding
to
encoding.symbol.ttf = windows-1252
See http://hutchinson.belmont.ma.us/tth/Wfonts.html for details and discussion.