It happened with 1586. 1695 seems to handle it a bit better in that under a controlled test if I shutdown iTunes and leave the Roku for about 10 minutes then it seems to sort it out. However in reality (with other things happening to the PC) it typically won’t connect without restarting the router or even the PC.
I’ve got someone working on getting me an ethereal trace for this. Maybe that will shine a light on it.