Hi,
Siduction-dynamic dms tries to detect display resolution of your's screen and to choose the appropiate background.
For that it should make a hardlink to
/usr/share/wallpapers/indiansummer/contents/images/$resolution.jpg for
/usr/share/wallpapers/indiansummer.jpg .
If $resolution fits display resolution the link is maded and siduction-dnamic-dms is ok.
Try to disable detect resolution script by commenting in lightdm.conf
display-setup-script=/usr/share/siduction-dynamic-dms/detect-resolution and see what's happen.
Thank you.