Error 'Undefined property' when loading model to controller

[eluser]Gavin Blair[/eluser]
You say 'lowercase_name' doesn't work on the hosting server, but 'Uppercase_name' and 'lowercase_name' both work on localhost.

Does 'Uppercase_name' work on the hosting server?

If so, you can fix everything by just editing the load line:
$this->load->model('Uppercase_name', 'lowercase_name');

That way referring to $this->lowercase_name will still work.