You can safely ignore the Ethernet/WiFi advice, that's only relevant for OnDemand and other internet-based functions. Live TV doesn't use the internet.
Your symptoms are odd, but I'm intrigued.. A V6 buffers on 6 channels at once and lets you rewind on all 6 by pressing "info", scrolling to the bottom panel and choosing between each tuner.
You can then rewind each individual channel/tuner to and from live TV. When this problem happens, are all tuners affected, or only specific ones?
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