Problem extending NGG

Hello, I’m extending NGG because I need an extra feature.

I’m trying to add a column to the “Manage Gallery” page with the filter “ngg_manage_gallery_custom_column”.

So I wrote :
add_action ('ngg_manage_gallery_custom_column', 'my_action');

Then I declared my_function in this way :
function my_action($column_code, $pid)

my_action is called but just one parameter ($column_code) is passed.

Where am I wrong ? NGG version is 0.99.1

Regards

—
Simone