asp.net mvc 2 customErrors iis 7.5 not working

My site is running on asp.net mvc2 and I'm using elmah for error trapping, not the handleerror attibute

if I browse to a non existing page like 'http://localhost:8095/Home/City/1/mtl/ko' I get t开发者_Python百科he IIS error 404 page

in web.config i have configured my custom errors

I even tried to set code in global.asax application_error and it's not being trapped there

why am I getting the IIS 404 error page ?

Now that I think about it I would like to log the 404 errors, where would I trap these in asp.net mvc ?

Thanks

I know this is an old question but thought I answer:

Elmah has filtering that you can apply: http://code.google.com/p/elmah/wiki/ErrorFiltering

Once you enabled the error filtering you need to modify the Gloabal.asax.cs to filter the error:

public static void RegisterRoutes(RouteCollection routes)
{               
    routes.IgnoreRoute("elmah.axd"); //Add this line to the register routes.
}

//ELMAH Filtering
protected void ErrorLog_Filtering(object sender, ExceptionFilterEventArgs e)
{
    FilterError404(e);
}

protected void ErrorMail_Filtering(object sender, ExceptionFilterEventArgs e)
{
    FilterError404(e);
}

//Dimiss 404 errors for ELMAH
private void FilterError404(ExceptionFilterEventArgs e)
{
    if (e.Exception.GetBaseException() is HttpException)
    {
        HttpException ex = (HttpException)e.Exception.GetBaseException();

        if (ex.GetHttpCode() == 404)
        {
            e.Dismiss();
        }
    }
}

But frankly I like to log everything including the 404 errors. This gives me a better view of how users are trying to get in or discover new features to support if need.

Other resources: http://joel.net/logging-errors-with-elmah-in-asp.net-mvc-3--part-3--filtering http://ivanz.com/2011/05/08/asp-net-mvc-magical-error-logging-with-elmah/