Working with Inkscape:
Saving a .svg file to an .eps file
One way to solve a bitmap problem.
If you have accidental blurs, transparencies, gradients etc and you are trying to save to an .EPS (inkscape) you will need to find them and fix it, before this will work.
Everytime you "draw" a shape or color it records each step.
This is one way to find a problem..
Open your file to inkscape and chose your illustration.
Under Edit: Open XML editor
and then Open Fill and Stroke and go to the CMYK tab.
Now you will have 2 boxes opened, with the illustration in the background.
On the last line in the XML box,