Extracting all color separations from a pdf

I am in need of extracting all the color separations from a pdf as separate images - including any spot/pantone colors. The code supplied under the PDFDraw sample works (Example 10 - Export separations directly, without conversion to an output colorspace), but when a spot color is on top of a color image, the exported separation for that spot color is blank. Any ideas on how to solve this issue? Thanks.

I have updated my PDFNet.dll and all is good.