Player or Router Issue?

I have a Qsonix 205 player which no longer connects to my network. Some months ago I changed providers to Viasat and they installed their Gateway modem/router. I think my problems started about this time. The Qsonix is connected ti my system via optical cable and to my network via ethernet  cable (and I have tried several).. The unit plays any of the 4,000 music albums fine from its internal HD over the optical cable. Yet when I look on my computer at  the  Network>Qsonix>music folder it says the folder is empty. Hardly! I went to the network setup tab in the Qsonix and did a DHCP autmatic configuration. . The unit registered  "success". On going to its diagnostics tab I got the following:  Gateway - succeeded, DNS - succeedrd, Connectivity - FAILED. So I logged into the Viastat Gateway and went to advanced settings>router settings>DHCP reservation table and found a block with headings of "name, assign ip, and  to this mac address". I went back to the Qsonix and got its ip and mac address, inserted them and hit "add". This obviously did not work because when I went back to the Qsonix diagnostics tab I got exactly the same readings as before, with the "connectivity failed" message . I just can't get the unit to connect to my network whereas previously it was. When it comes to networks I feel like a blind man stumbling around in the dark! I don't think it is a failure of the unit as it plays fine but I at a loss as what to try next to get it connected to my network. .