I am still having trouble getting Gizmo to connect to the MC Server on my Workstation. Sometimes it does, sometimes it doesn't. Mostly it doesn't. It seems quite random though.
However, if I just open PingTools on my phone, and do nothing else with it, then immediately after try to connect with Gizmo, it always works. Always.
Gizmo also always connects to my HTPC MC Server. Always. But it is running an earlier version of MC. MC25.0.73 I think.
So something is different between the two setups. But I have found nothing obvious. I have allowed for all the disk spin down, network NIC sleeping, etc. issues mentioned above.
I suspect there is a MC Server bug. When I open PingTools while viewing the server traffic in "Services & Plug-ins > Media Network", MC reports that PingTools calls from my phone to the server, running a http GET DeviceDescription.xml command. That is enough for Gizmo to connect. That could still a Norton for Mobile security software issue, but it looks like a MC issue more.
Maybe something has changed so that your phone loses its http connection to the server, and hence playback stops. Careful analysis with Wireshark may show that, if you know how to identify a lost connection. Or a closed connection. The caching in Gizmo may simply be allowing a new connection to be created before playback stops.