try dmzing the ip address you use to access the nas from within your network, try entering this into each device that would need port forwarding, if it works after dmzing you can disable it and add the necessary ports needed to be open in each device since some people don't like having every port open to their device.
Im only adding this because it looks like you just port forwarded the adsl router and not the rest of your devices. that are connected before your NAS.
