Save as optimized pdf, but size not reduced

Hi

I have several pdf files where I want to reduce the size, but it is not working with the option "Save as optimized pdf" in Adobe Acrobat Pro X.

As an example here is a pdf file I created with Inkscape and Latex: https://dl.dropboxusercontent.com/u/6521267/test4.pdf

This file has a size of more than 6MB and the Adobe space usage audit says, that 99% of the size is the image.

With save as optimized pdf, I can't reduce size. If I print the file as pdf, the size is reduced, but the link disappeared too.

Do you have an idea, how I can keep links but reduce the size?