I can see where this can become quite frustrating, but we really are trying to help you. 🙂
The fact that mDNS is returning errors suggests that there is some sort of issue. What does netstat report? Does it show an “*.mdns” entry under the udp protocol section? Does it show a registered address and inode under the active local sockets section?
It really would help if you could run a sniffer on your subnet in order to look at the quality of the QandA traffic. This would help determine whether it is a beacon or client issue. I am leaning toward beacon/server issue, but the traffic analysis would confirm one way or the other.