For the benefit of the list, I'll explain what the problem was:
Craig had several images in one SVG, and printing to PostScript was exporting all of them, not just the parts on the page.
One thing I've noted, however, is the useability of the program is reduced by only having one SVG image within an Inkscape session. For example, my diagrams are quite similar to each other, so I copy/paste objects from one diagram to another. By splitting into multiple files, when I want to make a change to one image, that will generally cascade into other images, requiring instance of Inkscape open for each SVG image. Perhaps it would be more useable by having a Tabbed feature in Inkspace for each open SVG file, allowing easy modification to multiple SVG images.
When exporting to PNG, you can choose to the export selection. Craig, I suggest you submit an RFE to add this functionality to the PostScript (i.e. printing) export also.
-trent