Better. Using the latest version, linked above, export with the LOSSLESS choice from the Home toolbar. That should do the job.
Consider cranking down the music, using the slider to the left of the track... 
Also, for efficiency and speed, try not to load clips that are not being used. ..
To purge them, select them all in a bin with <ctrl-A>, check the "do this for all" box and click the CANCEL (not the Delete) button. Then click the caret to the right of the SAVE button on the Home toolbar and choose Save AS. Give it a unique name, such as "<your project name>revised."