Why can't I export a Simulink block diagram as a vector drawing in 2013b?

I have previously exported my Simulink block diagrams as a vector drawing in encapsulated postscript format using the print command with success under 2012a. However, using an identical command, stored in a script under 2013b, the export is successful, but the image, when imported into my LaTeX document, appears as a bitmap.

This is the actual command I used in both cases:

print -s'foc_structure_model/Vector Controller' -depsc foc_structure.eps

I have tried various different options, but haven't managed to get a true vector image.