When I run iTunes on my laptop my Rokus lose access to Firefly. I have to restart the router every time. It doesn’t happen immediately but after a while. Firefly 1586 is served from another PC. iTunes sharing is turned off.
What does it do? Does it do the “library unavailable” thing? Does it stop playing if it was in the middle of playing?
And the server itself is a windows PC, right? Do you have any firewalls on it besides the built-in xp firewall?
if so, it might need to be set up to allow inbound multicast.