Live TV fine, but recorded TV stutters?

[dooger]

I recently switched to the DCR-2650 dual cablecard tuner (Comast), and when watching live TV (such as the Olympics HD), the playback is perfectly fine, but when playing back recorded TV of the same program, the playback stutters every 20 seconds or so (macro-blocks). And it always stutters in the same place, so the problem is in the recorded file, but I don't see the issue during live TV? I've greatly improved the problem by switching the OS to the blazin fast SSD and applying the common SSD tweaks, but all the media files (and hence, live TV buffer) are on a single 2TB SATA2 HDD. I've checked, and it's not the 29/59 issue. System is a newer z68 MB, core cpu, 64-bit with 8GB ram. Any ideas?

[Scallica]

Do the symptoms occur if you play the file using Windows Media Player or VLC Media Player?

Also, check the health of your hard drive using HDSentinel (http://www.hdsentinel.com).