Why wont mozilla firefox save my network options?

my mozilla firefox didnt work, so i looked at other posts and did what it said. Tools-%26gt;Options-%26gt;Advanced-%26gt;Network-%26gt;Setti... on auto detect proxy.


the problem is, everytime i close firefox and restart it, it goes back to the usual way and doesnt work. I find it very inconvenient to change settings everytime i want to use the internet. Thanks