ADE3000 ADSL Router - WAN IP not accesible form local network

[TP-Software]

Hi,

I have an Conexant ADSL Router (ADE3000) which is configured for a virtual
server on 10.0.0.5.
Everybody can reach that (http) server from the WAN site (the internet) by
using the WAN IP or the DNS name linked to that IP

But I can't, from within the network I cannot reach the server with the WAN
IP, only by specifing the local IP
Which is not good since I want to be able to use the DNS name.

Can anybody help me ?
Thnx.