[gollem] Can't select a backend

[Rickard]

I have just setup Gollem so that I can host some files for my users.
The thing is, I want the filearea to be a specific directory on the server.

I have setup the /<path-to-horde/FileArea to be owned by the webserver user and
group, and set it to chmod 700.

However, I find no where to select the preferred backend.
I don't want my users to choose a backend, but instead be directly logged in to
the file area.
Preferrably without another authentication, but this is secondary and not as
important.

I have tried to make a backends.local.php where I only have the
$backends['file'] = array(
    // Disabled by default
    'disabled' => true,
.....

if I select that the backend list should be shown, I only see "FTP Server" in
the list.
If I select to hide it, it is the same, defaulted to FTP, and I can't log in.
How should I do in order to make file backend to be default, and optionally, to
have my already authenticated users to be thrown right into the filearea without
a second authentication?

Best regards,
/Rickard