BG image in header mod - Steakhouse j3

hi,
As i worked on the sample package, all goes good, i changed the header bg image and it worked.
But as i tried to apply the template to the existing site (i put it on local for the test) to keep the content, i'm no more able to place an image in the header bg... it still whyte... can you please help me?
PS: sorry for my bad english, i hope to be understood.

Thanx

solved thanx to ""frontpage" not detected in multilingualmode" post