Invalid argument in common.php line 4309

I seem to be having an issue with the function "get_radio_choices". I have a form with a list control that I populate one of the columns with selections using the following code in functions.php

add_filter("gform_column_input_11_2_1", "set_column_input_food_diary", 10, 5);
function set_column_input_food_diary($input_info, $field, $column, $value, $form_id){
    return array("type" => "select", "choices" => "Breakfast, Lunch, Dinner, Snack");
}

The options appear fine on the form and I can submit the form but when I display the results using the Directory plugin I get an error occuring.

This only happens when I add more than one row to the list control.

Any ideas??