Hello, so ran by your post when searching for the same thing. I couldn't open my video with multiple tracks in Camstasia, but was able to cycle through them with VLC player. What I did was used handbrake. In there I was able to select the video and which of the 2 audios that I wanted to export it with. I exported 2 versions of the video... each with a different audio track. So now I have 2 videos... 1 with my desktop audio and 1 with my mic audio. I can now edit as I see fit. It's a real shame that this can't all be accomplished within camstasia.