Mimin Server Disappearing!

[pmfortune]

I have successfully used MinimServer for several years on my ARM QNAP. Its now getting a bit long in the tooth and given I have a MacMini (Running Yosemite Server) I thought I would transfer my music to a drive on the MacMini and install Minimserver on the Mini.

When I installed it and start it running it it shows up on MinimWatch on my iMac that is physically connected to my LAN and also is also visible in Kazoo on that machine. Howvever I can't see it at all from any of my WiFi devices (iPhone, iPad & MacBook Air).

After a while it disappears from the devices that are directly connected to the LAN (first from Kazoo - then from MinimWatch). This never happens on the QNAP version running on exactly the same network - its always visible on all devices.

I have performed a completely clean install of Yosemite (server) on the MacMini and currently MinimServer is the only software running on it (apart from the OS !).

My router is a Linksys E4200 with the latest firmware installed (1.0.06) & I have a Cisco SG200 26 Port Smart Switch (so I can run my Linn system in Multicast). The configurations of both the MacMini & QNAP ports on the switch are identical.

Does anyone have any ideas what I need to look at??

Thanks

Peter-Marc