S-Note: Graphs miscoloured when importing PDF files

[Nicolai Bisgaard]

In my S-note when i import PDF files, like:

https://www.dropbox.com/s/x06jxr5gykkf89q/11464 Lecture 4.pdf

All the graph figures gets a colored background which makes it very hard to read.
For example the graph on the right of page 3 gets a black background which overrules everything else on the figure.

Any ideas how i can prevent this?