Copy Protection and Comcast Problems

I got this message on my TiVo Series3.

Subject:    Information Regarding Your Premium Channels
From:       TiVo Customer Support
Date:       Thu 5/3
This is an important message that may impact your ability to
receive premium channels. Please read it carefully.
Comcast has recently announced plans to enable their Copy
Protection Management Systsm in the Bay Area.
As a result, in order for your CableCARD(tm) decoders to
continue decrypting premium channels, they will need to be
properly "paired" within the Comcast system.
Here's how to ensure each of your cards is properly paired:
-From TiVo Central, select Messages & Settings. Then select
Settings, Remote CableCARD & Devices, CableCARD Decorder,
Configuring CableCARD 1, CableCARD Menu, Condition
Access
You should not be on the Motorola Conditional Access
CableCARD screen. If your card is paired, you will find a line
that says "Host Validation: Valid." This means that your TiVo HD
expierience WILL NOT be impacted by theic change, and there's
nothing further you need to do.
However, if it says "Host Validation: Unknow" your card is
not properly paired.  Pleace contact Comcast Customer
Service and share the information from the CableCARD data
screen with the agent assisting you.
Please make sure to repeat tthe above process with
CableCARD 2.

Even though I was able to record premium channels on both tuners, I checked the status of my CableCARDs.  When I did I noticed that one of them was not paired correctly.  I called Comcast's customer service, and they were not able to get it paired over the phone, so I scheduled a technicians visit.

The technician brought a new CableCARD.  It took a while for the card to be activated, but the card was correctly paired.  Then a few days later, I noticed that several recordings had no video.  It turned out that at some point after the technician visit, the CableCARD lost the knowledge of what channels I are subscribed.

Once more call to Comcast got the CableCARD correctly working.