Hash symbol in URL causes a problem

Hi
I'm currently using Codeigniter version 3.0rc3, but I've had the same problem in version 2.2 as well

My routes.php look like this

PHP Code:

$route['event/:num'] = "events/event"; 


config.php

PHP Code:

$config['permitted_uri_chars'] = 'a-z 0-9~%.:_\-'; 


If I try to reach, for example

Code:

http://example.com/event/32

I'm getting expected results

If I try to reach

Code:

http://example.com/event/asd

I'm getting 404 Page Not Found
Also expected

If I try to reach

Code:

http://example.com/event/+34

I'm getting An Error Was Encountered The URI you submitted has disallowed characters.
Also expected

But I try to reach the same controller with just a hash symbol

Code:

http://example.com/event/#

I'm getting a database error because of if

I would appreciate if somebody could help me fix this problem.
Thanks.