This is such a common issue on the Media Center newsgroups that I thought I would talk about it here. It comes up daily, so I think it is safe to assume that many people are affected by this, especially those in the Do -It-Yourself (DIY) crowd [most OEMs ought to know about this issue, and should have implemented the fix that I describe below].
For those of you with AMD X2 (dual core) CPUs, you will likely run into issues with Live TV or Recorded TV. Symptoms include stuttering of content, to freezing and even crashes of the computer.
The issue is related to CPU power management issues with dual core processors. Without the fixes, the timing indices of the Live TV/Recorded TV are affected, due to various timing issues, which leads to stuttering (and in extreme cases, freezing or crashing) upon playback (yes, even Live TV is recorded and played back, albeit rather quickly).
For those of you that have recorded a lot of content with an AMD X2 CPU before updating the CPU driver, unfortunately, their timing indices will remain affected (i.e. the updated CPU driver does not fix existing recordings). Recorded TV content created after the installation of the CPU driver should be fine as reported by nearly everybody on the newsgroups that have implemented this fix.
Moral of this story? If you have an AMD X2 CPU, install the latest AMD CPU driver immediately, otherwise, your Recorded TV (and Live TV) will be suffer from stuttering that can't otherwise be fixed.
Update - July 24, 2006 - Link to blog entry about updated revision (v 1.3.2) of the AMD CPU Driver and updated links in this blog entry