It looks like the instructions on the site are incorrect
Hello. Thanks for the quick reply. Here are the directions from the download page for adding these presets to CSSSculptor:
To use these files, download and save locally. Extract the XML files for each layout type to a local folder. Then, open the CSS Sculptor Layout Manager (Insert > WebAssist > CSS Sculptor > Layout Manager) and select Import. Locate the XML file on your local system specific to the layout you wish to work with and click OK. The layout will be imported; if any layouts with the same name exists, the new layout will have the word 'Copy' appended.
You had me import the zip file into CSSSculptor and, as you mentioned, I got a dialog asking if I wanted to keep running the script but eventually it worked. Great! Also, the directions must be for DW CS4 as with CS5 the way to do this is through Insert>WebAssist>Preset Manager.