In Fuduntu, if you have other internal partitions ( when you use dual boot with Windows, for example), you will see this dialog box asking for the root password when you try to mount these partitions:
To disable this dialog box and mount the partitions automatically when you click on it, you can hit Alt + F2 then run the following command:
beesu gedit /usr/share/polkit-1/actions/org.freedesktop.udisks.policy
A dialog box will appear to ask you to enter the root password and then gedit will be launched for you to edit this file as root. Just scroll to line 30, where you see the line:
Here is a screenshot:
Just change this line into:
Save the file and everything is done, from now you can mount other partitions by double-clicking on it without the need of authentication.