In one of my profiles I have: user_pref("general.useragent.override", "Mozilla/4.0 (compatible; MSIE 6.0; Windows 98;)"); this line does not seem to have any effect. STEPS TO REPRODUCE: 1. create a new profile and load any page with it (will create prefs.js) 2. exit Mozilla 3. add the above user_pref line to the file 4. start Mozilla with this profile again ACTUAL BEHAVIOUR: about: shows the builtin default UA string, which is: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.5b) Gecko/20030919 I also verified with a packet sniffer (ethereal) that this is also the value in the HTTP header "User-Agent" that is being sent in the requests. about:config show the correct overridden value, this is why filed the bug to Networking rather than Preferences. EXPECTED BEHAVIOUR: about: shows the string from the "general.useragent.override" preference and this is also the string sent as "User-Agent". PLATFORMS & BUILDS TESTED: Bug occurs in Mozilla 2003-09-19-05 trunk on Linux. Bug does not occur in Mozilla 1.4 on Linux Bug does not occur in Mozilla 1.5RC1 on Linux

After a restart, worksforme in build 2003092105 (latest trunk) on Mac OS X 10.2.6

Reporter: Do you have a user.js which overrides this prefs.js setting ?

worksforme with linux CVS trunk (today) debug and binary 2003091822 build.

*** This bug has been marked as a duplicate of 219456 ***

I'm not using a "user.js" and I'm not using a proxy.

Mats: many symptoms of the same problem. bug 219456 is about the fact that the user_pref commands were being essentially ignored.

Thanks for the clarification. It works fine in 2003092305 trunk Linux. -> Verified