Problem with Upload config file_name

[eluser]old_guy[/eluser]
I'm experiencing a problem with the changing the file name within the upload config array. My code is as follows;

Code:

$config= array(
            'upload_path'=> './uploads/',
            'allowed_types'=> 'csv',
            'file_name'=> 'test.csv',
            'overwrite'=> FALSE,
            'remove_spaces'=> TRUE,
            );
$this->load->library('upload', $config);

The upload function works fine. The $conifg array contains the right file name

Code:

./uploads/ [allowed_types] => csv [file_name] => test.csv [overwrite] => [remove_spaces] => 1 )

Checking the uploaded data I get the following:

Code:

Array
(
    [file_name] => csvTest.csv
    [file_type] => text/tsv
    [raw_name] => csvTest
    [orig_name] => csvTest.csv
    [file_ext] => .csv
)

The file name does not change. The file gets uploaded with its original name.

Any help discovering why this is occurring would be greatly appreciated.