The relative URLs in your stylesheet are probably incorrect. Keep in mind that relative URLs in stylesheets are relative to the location of the stylesheet, not the parent HTML document. Try changing to complete URLs (ie. 'http://www.example.com/img/bg.PNG'). If those work then you know your relative URLs are incorrect.
You seem to be mixing "specific" (-image) rules and "shorthand" background- rules. Believe, when you specify background-image, you do not include other aspects (such as no-repeat). Likewise, when you use background: shorthand, you have to include at least one other related property (such as color, position, etc.).
Also wonder about the one that has no position specified?