Not work "Dark image background"

In Quark Child Ecommerce does not work the "Dark image background" while the "Dark image background on frontpage" works. What is the cause ? I would add that in the recital Quark everything is working properly.
Regards

Polish version
W Quark Child Ecommerce nie działa opcja "Dark image background" natomiast opcja "Dark image background on frontpage" działa. Co jest przyczyną ? Dodam że w samym motywie Quark wszystko działa poprawnie.
Pozdrawiam

Hi,

Could you please provide me with a URL to your website and back-end access via PM (click the “Private Message” text underneath my avatar) so that I may analyze it? Because I can't see any problem with that on my quark ecommerce version.