ReadyNas duo v1 Firefly server can't be seen by soundbridge

Hi there I hope you can help me with my set up or point me in the right direction. I have a pinnacle soundbridge m1000 running v 3.0.44 which refuses to see my firefly server, which is running on a readynas duo v1

The soundbridge is connected via Ethernet to a 4:1 powered switch which is connected to a home plug, connected to the router (a technicolor gateway tg582n). The readynas is connected to the router direct via Ethernet.

The firefly server can be seen via my iMac as a iTunes server and I can play tunes off it so I don't think the issue is with the router, nor the readynas. However the soundbridge cannot see the firefly server. It can see other servers (I also have a readynas duo v2 running logitech's squeezeserver) and it sees and connects fine to them, but not the firefly server.

I've also switched the soundbridge over to wireless to eliminate the switch and the homeplug and still no firefly server.

on Frontview Firefly says v1.0.0 and in about/firefly (on the firefly config pages) says this: Firefly Media Server, version svn-1676.

Any ideas?