Updating on previous findings.
Using Pitivi 0.13.5
1. (preview cuts off mp3 tracks): When playing the voice-over (mp3) segment in the "preview" to line up the timing of the end of the voice-over with the next video, the voice-over gets cut off at the end, when I play the mp3 on any other play it's end is "normal". This concerned me and I figured we may be back to the same kind of problems I discussed in my last email, so I didn't produce the voice-over videos, I just wanted to test how the rendering would come out. I rendered the project with one white background image and just the video from the two segments that already had video. Here's a screenshot of the timeline: http://www.csrtechnologies.com/Screenshot.png
On other projects, this problem still exists. When previewing a project (pre-render) the mp3s get chopped off (the sound of the mp3 stops before the actual mp3 recording ends). Playing the mp3 on any other player and you hear all the way to the end of it. Just not in pitivi.
2. (rendering video speed varies): Well, everything "works" with the exception of the two videos that were inserted. When they go to play (in the final rendered video), their audio is the right speed but the video playback is too fast, it actually ends and sits on the white background for a little while before the next mp3-only segment picks up. I just noticed that I accidentally didn't use the original video when inserting those two video segments, so I'll be trying it with the original and see if it makes a difference. One thing to note, the final is 25fps and the two inserted videos were 15fps. Both are flv, my thought here is maybe the "render" code just copied the frames frame-for-frame out of the inserted videos into the final and naturally ran out of frames because of the frame rate difference.
This problem turns out to be a real problem for pitivi. If your source video is 15fps and you are rendering a 25fps video, it doesn't create any tween frames to fill the other 10 frames needed per second. So a 10 second 15fps video has 150 frames, and when you render that into a 25fps video the video will all be gone in 7 seconds (150 frames / 25fps).