weird problem with URL path

Hi,
I just run into a weird problem with my new updated apache server.
If I type in http://mydomain.com/directory/ the server loads up the
default index.htm just fine. But if I remove the back slash of the
URL, ie. if I type http://mydomain.com/directory, then an error
message appears, and it seems that the browser can't locate the page.
I remember my old apache server has no problem with this.

Does anyone know how to fix this?

Many thanks.

John
zyang.TakeThisOut@waveline.comn