CustomErrors! What is going on?

[shapper]

Hello,

I have the following on my ASP.NET web.config file:

<customErrors mode ="On" defaultRedirect ="/Error/Generic">
<error statusCode ="400" redirect ="/Error/Http/400"/>
<error statusCode ="401" redirect ="/Error/Http/401"/>
<error statusCode ="403" redirect ="/Error/Http/403"/>
<error statusCode ="404" redirect ="/Error/Http/404"/>
<error statusCode ="408" redirect ="/Error/Http/408"/>
<error statusCode ="500" redirect ="/Error/Http/500"/>
<error statusCode ="502" redirect ="/Error/Http/502"/>
<error statusCode ="503" redirect ="/Error/Http/503"/>
<error statusCode ="504" redirect ="/Error/Http/504"/>
</customErrors>

Something very strange happens. Every time I refresh a page the error
is fired but the HttpCode is always null.

I have no idea why this is firing because no error happens.

Could someone help me out?

Thanks,

Miguel