why is the date of a TCD649080 important?

[replaytv]

I have noticed a couple TiVo Series 2 TCD649080 Receiver With LifeTime Service up for sale on ebay over the last couple of weeks, and someone usually asks what the date of manufacture is. Is there something of significance to the date on a TCD649080?

[unitron]

I have noticed a couple TiVo Series 2 TCD649080 Receiver With LifeTime Service up for sale on ebay over the last couple of weeks, and someone usually asks what the date of manufacture is. Is there something of significance to the date on a TCD649080?

They're probably confusing it with either the Series 1s where lifetime purchased on or before January 21, 2000 was one-time transferrable, or with the Series 1s manufactured before October 2000 that can be set to be useable manually without a subscription.

If it were me, I'd want to know the TSN to check it with TiVo Customer Service to be absolutely certain about the lifetime status.