If you get following warning(s) on your site:
Strict Standards: Non-static method ... on line XX or
and you are running Joomla! 2.5 or 3 or any later version, go to your Joomla! Global Configuration - Server and set the parameter Error Reporting no None.
Strict Standards warnings are no errors, these are messages for developers and such messages should not be enabled on production site.
Changing php error reporting on server side (php.ini)
You can disable Strict Standards on your server too, in php settings.
Go to your php.ini file and disable Strict Standards on your server.
The attribute is called: error_reporting
error_reporting = E_ALL | E_STRICT
error_reporting = E_ALL | E_DEPRECATED,
(of course Error Reporting parameter in Joomla! Global Configuration can overwrite this settings)
If you are not able to change the php.ini on your server, try to ask your webhosting provider.