This might be a 9.3 bug, or I might be missing something. "Only show when" rules are not working for background images in my copy of mac 9.3. I've replicated the problem in the attached workbook. A USA map should appear behind the graph when (and only when) USA is selected in the filter. I don't see the image. The image is there, and everything works when you remove the "Only show when rule" (Map>BackgoundImages>Sheet1; Click the only rule, hit edit, hit options, remove the 'Country:USA' requirement... the flag reappears). I want that map only to appear when USA's data is selected.
Issue solved, with a huge thanks to Sarah Battersby.
Simple fix: The 'Only show when' rule requires the shown value to be in the view (in a row or column) - not just in the filters. Throw the Country variable into the view, and everything works as expected.