I'm using iTunes home sharing between two Windows 7 64bit PCs and one MacBook Air, over a private VPN using Hamachi.
It works great, but after playing the music for about 30 minutes ~ 1 hour, the home sharing is just disconnected and the shared PC does not appear anymore.
I can make it run again by restarting iTunes at the both sides, but it's quite annoying.
Is there anyone who has solution to this problem?