Error - Network Clock is not Locked - Video Satellite

[Naught1]

Running Video Satellite LE, we recently started seeing more and more "Cannot start Playback. Network Clock is not Locked" errors. In a 90-minute playback this error popped 5 times. Clicking the OK button allowed playback to resume. Naturally this happened during a screening with the Director.

We've been running Video Satellite LE happily for about a year, and this problem only came up once or twice per week.

Per previous threads, I've verified that all three systems are running the same sample rate and timecode settings.

The LE and 2 HD rigs are running 8.01cs1 instead of 8.03 due to 3rd party software limitations (Virtual Katy).

Since this points to a network issue, I should point out that the 3 systems connect to the same local gigabit switch, which then goes to a master gigabit switch, then on to the router/firewall.

So here are my questions:

1. Could this stacked switching be the source of the problem? We haven't previously noted problems with speed over this connection, but it's possible that certain types of traffic may be limited by it.

2. Or does the local switch handle the traffic between the systems?

3. Since the MacPros these run on (all identical 2x2.66 dual cores) have 2 ethernet ports, can one of them be dedicated to run the VS traffic? That is, can I simply connect all 3 to the same dedicated gigabit switch (which would do nothing else) and somehow get the VS networking to use only the dedicated ethernet ports?

Thanks for the responses!