Just to clarify, you have 2 x V6 & 1 x TiVo? Check here if you want to make sure, although I think that's what you're reporting.
Picture pixellation and breakup can often be a symptom of poor TV signal, or in some cases HDD issues - it all depends on your circumstances.
Can you view live TV channels ok on any individual box? How about if you pause & rewind live TV?
On any box that works ok for live TV, I'd be minded to start swapping them between different rooms - although I suspect you may have a mixture of faults.
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