Why is Background Music so loud when I convert PPT to Video

I have created PowerPoint slide presentations with narration and added music backgrounds and when converted to video, no matter what program I use, the music is too loud. I have set the volume in PowerPoint for the narration to high and to very low for the music. It plays perfectly in PowerPoint. When I used a program like Moyea PowerPoint to Video or Leawo PowerPoint to Video (as well as others) the music is very loud!

I have installed the ispring which can convert PPT to SWF file and it is perfect. However this makes it more difficult to put the file on a CD or DVD to share. I would like it in either FLV or MP4.

Any idea how to solve this?!!!