Weird Network Encoder Problem

[interloper]

Some background: I am running two Sage servers, one of which is a network encoder. The "master" server runs on XP, the network encoder on Vista. Other than for setup/maintenance, I almost exclusively access them through an HD100 extender. Both servers are connected over a gigabit link, and are running Sagetv 6.5.12, while the HD100 is running on the last beta firmware that came out. The network encoder has two ATSC tuners, a Hauppauge 1600 and a recently added Onair GT.

The problem I am seeing is that when I am using my HD100 to watch a channel that is being tuned via the network encoder, occasionally the tuning seems to glitch such that the channel being tuned physically changes on its own. In other words, I could be watching a hockey game on CBC, and after a minute or two the video abruptly changes to another random channel altogether. However, Sage itself has no idea that the channel has changed, and will still display that I am tuned to the original channel.

In my experience, when it happens it is usually within a minute or so of tuning the channel. When this happens, simply attempting to re-select the original channel is not effective, it pretty much takes a restart of the Sage service on the network encoder to bring back some stability. Channels being tuned through the master server are not effected.

I can confirm that this happens on both tuners on the network encoder, so it is not a tuner-specific problem. I've never seen it happen on my master Sage server. I have only seen it happen while watching "live" tv, as opposed to shows pre-recorded. However, the network encoder is tuning channels that I don't watch or record from often, so this may be coincidence.

If anyone has seen this before, or has any ideas, I'd appreciate any insight!