Scripting Keynote 6.0

I’m trying to write an Applescript to export the images from a Keynote presentation using Keynote 6.0, which has now added that option. I can export a movie, a PDF, and every other type of format except for an image. Here’s what I’m doing and it doesn’t do anything, doesn’t even give an error. Any suggestions?

tell application “Keynote”

 export front document to file "HD:Exported" as image with properties {compression factor:0.9, image format:PNG, export style:IndividualSlides, skipped slides:false, all stages:true }

end tell