I am uploading a csv file with this code.
$config['upload_path'] = './uploads/'; //config overiding
$config['allowed_types'] = 'csv|xlsx';
$this->load->library('upload', $config); //loading upload library
it works fine but in csv content if there exist a word import CI throw an error message
The filetype you are attempting to upload is not allowed
and if I change it with Import it works fine.
and it only happens on live server
PHP Version 5.3.10-1ubuntu3.2
it works fine on localhost.
Can some body guide me what that was..!

Localhost setting:
PHP Version 5.4.3 WAMP Apache Version 2.4.2
Live Server setting:
PHP Version 5.3.10-1ubuntu3.2
To avoid I use PHP
move_uploaded()& it worked fine