I have just edited a video that is 3:21 seconds but when I save the output. The new video is now 2:41 seconds. I can visibly see the video is moving faster then it should and I can't put the sound back in without that 40 seconds.
I did several test videos prior to this one without this happening and I haven't a clue how to fix it. Any help would be greatly appreciated (A solution would be even better though ;) )
What is the framerate of the original video? What is the project framerate in particleIllusion? If they don't match, that would explain it.
When you hit the "play" button in particleIllusion, does the movie look correct (but it probably won't be playing fullspeed)?
In the Preferences dialog, is the "use new method for loading AVIs" option checked or unchecked? (Try changing it)
If all else fails, just turn off the bg image and render just the particles with an alpha channel, then composite over your movie in another app (since you need to use another app to put the audio back anyway).