I downloaded the current build of PD8 and installed it. I also downloaded the video driver, but I haven't installed it yet. (I figure one change at a time, but I'm excited to get drivers that are only a week old!)
The immediate problem is fixed. I can make the trim to the audio track, reposition it, and everything is fine. But there's a new wrinkle.
After I trim the voice track, when I double click on it to adjust the trim I receive a message: Warning. CyberLink PowerDirector cannot trim the portions of the selected audio clip indicated in red, because it is restricted.
I've done a little experimenting to see what kind of pattern there is to what portion of the clip has become "restricted," and I think I have it. Here's what I did:
1. Drag the sound clip to the voice track.
2. Double click the voice track to bring up the trim window.
3. Trim, say, 1:00:00 (one minute) setting the mark in.
4. Drag the clip so that the trimmed clip starts at 0:00:00 on the time line.
5. Double click the clip again, see the warning message.
6. Close the trim window.
6. Drag the clip to the right on the time line as far as the portion that was trimmed. Double click to bring up the trim window, now there's no restricted portion.
Looks like having a trimmed portion of a clip "hanging over" the beginning of the movie causes problems. Better to have a warning message than a crash, but better yet being able to adjust the trim point without having to reposition the clip.
Thanks for your help.