I'm carrying this over from another thread that had a more specific title. Through some investigation, it appears that--on two completely different machines with files from different cameras--I am unable to properly play back interlaced AVCHD video in Premiere Pro.
The video bounces up and down a few pixels at a few Hz, as if the camera was unsteady. In Windows Media Player, the video is rock solid. In Premiere Pro, both in source monitor and rendered video, it bounces.