web.config custom 404 error not working in IIS5

Question

Hi,

I've made a custom 404 error page in my codebase and have the following lines in the web.config to direct the customer to this page in the event of a 404.

<httpErrors errorMode="Custom">
<remove statusCode="404" subStatusCode="-1"/>
<error statusCode="404" prefixLanguageFilePath="" path="pgeNotFound.html" responseMode="File"/>

The problem is that I'm staging this in IIS5 but my production and local dev env are IIS6.

Does IIS <6 not listen to custom errors in the web.config?

How come?

Any input all greatfully received.

thanks,

ben