su_slider duplicates himself

[su_slider source="media: 1140" link="image" width="400" height="200" responsive="no" title="no" centered="no" arrows="no" pages="no" mousewheel="no"][su_slider source="media: 286,642,284,639" width="400" height="200" arrows="no"][su_slider source="media: 286,640,284,639" width="400" height="200" arrows="no"][/su_slider][/su_slider]

my slider:
[su_slider source="media: 1140" link="image" width="400" height="200" responsive="no" title="no" centered="no" arrows="no" pages="no" mousewheel="no"]

wtf is this:
[su_slider source="media: 286,642,284,639" width="400" height="200" arrows="no"][su_slider source="media: 286,640,284,639" width="400" height="200" arrows="no"][/su_slider][/su_slider]

Anyone know?