When the Seek Slider is positioned over clips in different tracks and you add a media file, you can choose to add to either the beginning of the movie, the end, or at the Slider position.
Lock all tracks that you want to keep intact before adding the media file. The Lock option is available for every track and forms a column towards the left of the timeline.
Look up Video Edit Magic's help for details. You can also view the help online. For more information Lock option, visit:
http://www.deskshare.com/vem-help/UnderstandingLinkLockHide.aspx