are the clips you are match framing from in the timeline linked to the new audio?
i know one doesn't always have the audio in the timeline, but if you do ty to keep it linked.
otherwise / also,
are the timeline clips AFFILIATES of the synced MASTER clips?
if you park on and select a timeline clip and hit Shift F does it take you to the synced clip in the browser?
have you trashed your preferences?
nick