Moved span

I use the marinelli theme in giordani subtheme. I put (not in the original theme) the site title and the site slogan inside a couple of span label(...) (one to the title and one to the slogan).

After install the PNG Behave module, and add the span classes (.trans in may case)to the CSS Classes/Selectors to Include: section of the PNG Behave module settings page, the span (with its background image of course) appear about 15 or 20 pixel over it original location. The location came to his right place when i just erase the classes from the CSS Classes/Selectors to Include: section.

The classes, just apply a semitransparent image to the background span to allow the title to be see over the image bottom.
The content of the classes is:

.trans {
background-color:transparent;
background-image:url(../img/fondotit.png);
background-attachment:fixed;
background-position:center;
background-repeat:repeat;
padding: 0px 5px 0px 5px;
}

I attached 2 images with the classes in the CSS Classes/Selectors to Include: section. ---sinbehave.jpg and without the classes in the CSS Classes/Selectors to Include: section. ---withoutbehave.jpg.

I hope it help yo undertant.
Thank and Excuse my English please