TiVoHD - Clock periodically self-resets two minutes slow?

[Rosenkavalier]

My relatively new TiVoHD (Feb or Mar of this year) is all of a sudden exhibiting an odd but somewhat consistent behavior. I will start to watch a recording, and find that it began recording after the actual start time. When I stop playback and check the TiVoHD's clock, it will be two minutes slow compared to the atomic clock (which I check live on-line).

If I force a network connection, the TiVoHD's clock will re-sync and correct itself. But then a few days later, the clock will all of a sudden be two minutes slow again.

I do have a CableCard in my TiVoHD - is there any chance that my cable provider (Charter) is sending the unit a time signal via the card, and it is incorrectly resetting the clock between network connections?

Otherwise, what would be the basis for this?

[lessd]

My relatively new TiVoHD (Feb or Mar of this year) is all of a sudden exhibiting an odd but somewhat consistent behavior. I will start to watch a recording, and find that it began recording after the actual start time. When I stop playback and check the TiVoHD's clock, it will be two minutes slow compared to the atomic clock (which I check live on-line).

If I force a network connection, the TiVoHD's clock will re-sync and correct itself. But then a few days later, the clock will all of a sudden be two minutes slow again.

I do have a CableCard in my TiVoHD - is there any chance that my cable provider (Charter) is sending the unit a time signal via the card, and it is incorrectly resetting the clock between network connections?

Otherwise, what would be the basis for this?

A bad coin battery ? that inside all TiVos, the clock in TiVo is not running correctly (most TiVo internal clocks run seconds a day off not minutes). Only a call home can set the TiVo clock.