[Solved] CI WebApp loads blank screen on production host but not on local

[eluser]it.peds[/eluser]
Prefix should be 'MY' not 'My', but it is strange that MAMP has no problem but virtual shared hosting has problem.

Everything works when it is in local host, but blank screen in production server.
I turn on error reporting for both index.php/error_reporting(E_ALL) and $db['production']['db_debug'], but nothing.
I try typing full urls. Correct ones get a blank screen, wrong ones get 404.
At the end, I use print_r and var_dump to check where code executing stuck. after or when executing codeigniter.php line 250

Code:

include(APPPATH.'controllers/'.$RTR->fetch_directory().$RTR->fetch_class().'.php');

no more messages output.By 'no more', I mean no output from print_r in the codeigniter.php after line 250, router.php, and all my functions in all my controllers. My controllers are like this,

Code:

// in application/controllers
class Defaul_Controller extends My_Controller {
    public function __construct()
    {
        parent::__construct();
        ... load some models ...
    }
    public function index()
    {
        $this->other_function();
    }
    ... more functions ...
}
// in application/core
class My_Controller extends CI_Controller {
    public function __construct()
    {
        parent::__construct();
        ... load some models ...
    }
    ... more functions ...
}

I am waiting the hosting company emails me the server log, but in the same time, I am hoping someone can help me solve this problem

[eluser]jmadsen[/eluser]
Linux is case sensitive; Mac and Windows is not. So My_ would work fine on those systems but blowup on Linux

[eluser]Beginers[/eluser]
desame as me it displays blank screen in the server but not in the local. why is this happening?

[eluser]it.peds[/eluser]
As what jmadsen says.