I'm not completely sure what's the problem....the background should be black rigt? And it ain't black after you published it? is that the problem?
because then there might be a problem with the layers, or the settings of the publish thigy....if that ain't the sollution or problem, well then I don't know
If that is the problem, at the layers you should uncheck everything(no red crosses)
Maybe you could put it back so I can see what's wrong.