Check if you are in a private browsing, go to Tools >> Options >> Privacy >> Firefox will: change to Never remeber history, also go to about:config and search for geo.enabled change its value to 'true,

• about:config

You can inspect and manage the permissions for the domain in the currently selected tab via these steps:

• Click the "Site Identity Button" (globe/padlock) on the location bar
• Click "More Information" to open "Tools > Page Info" with the Security tab selected
• Go to the Permissions tab (Tools > Page Info > Permissions) to check the permissions for the domain in the currently selected tab

You can inspect and manage the permissions for all domains on the about:permissions page.

• https://support.mozilla.org/kb/how-do-i-manage-website-permissions

Delete the permissions.sqlite file to reset all permissions.

This doesn't work in Firefox 27!

See http://www.techsupportalert.com/content/how-enable-or-disable-location-sensing-windows-7-and-8.htm

it's already done and didn't work...

Yes it does. Worked for me.