Edited file looses info

[ktb <ktb@binary.net>]

    Hi,  I'm trying to edit .netscape/prefereces.js
I have edited a few files before with no problems but with this file
what I've added doesn't stay in the file.  I'm trying to add this line,
user_pref("mailnews.reply_on_top", True);
I am using joe and when I exit with 'ctrl k-x' it says that the file is
saved.  I am in root when doing it.  I restart xdm and look at the file
and the line is gone.   I contacted the netscape unix news group about
this but no one seems to know what is going on.  What am I doing wrong?
I used ls -l on the file and got -rw-rw-r--  which if I'm right that
means I can read and write to the file and I understand when editing as
root none of that matters so I'm clueless.
Thanks,
Kent