Hi, It only cuts all tracks if you have no track selected.  Click on the track that you want to cut so that it is highlited, and you will only cut that particular track.  If you are using MEP 2013 or 2014 if you do not want the audio track cut you need to seperate it from the primary video track so that it has it's own track then select what you want to cut.  You also (depending on the version or MEP) need to "ungroup the primary video from audio, or ungroup any tracks that you have previously grouped.

George