User.js windows 98 mozilla 1.7.7 problem

When i create values in my user.js file ( which i created in the profile 
directory) they are not being loaded into the prefs.js file as mozilla 
is loading

The format of the user.js file is as follows

user_pref("signed.applets.codebase_principal_support",true);
user_pref("general.skins.selectedSkin", "modern/1.0");
user_pref("capability.principal.codebase.p0.granted","UniversalXPConnect");
user_pref("capability.principal.codebase.p0.id","http://3333333");

This workes fine on windows XP for the same version ( have not tested on 
  windows 2000)

Has anything changed in the latest release of mozilla or can anyone 
suggest more things i can test?


I am also seeing some strange behavior with the writing of the prefs.js 
file.

For instance if i manually change the theme from within the browser ( to 
modern) then the entry in the prefs.js should change to

- user_pref("general.skins.selectedSkin", "modern/1.0");

After i close the browser. It does this the first time.

Then if i open mozilla ( modern theme now displayed) and then close it.

I check the prefs.js again and the line is now missing. However when i 
open up the browser modern theme is still displayed.

Has the area to record user preferances changed? or is this a bug

Cheers

Murray