Arduino Uno and Elecfreaks CAN-BUS shield voltage issues

Hi everyone,

I recently purchased an Elecfreaks CAN-BUS shield. I downloaded the Seeed Studio Can Bus library from github and tried some of the examples. The shield reads the can bus messages just fine, but when i try to send messages i have an issue. When the bus is on dominant state CAN_H is 1 V and CAN_L -1 V, both are 0v on recessive state. Here is a picture below;

(Link: Imgur: The magic of the Internet)

I think i have connected the shield right to my Uno and i am using D10 as the SS pin at the moment. Could it help using D9?

I think the lib from Seeed Studio expects the SS to be on pin 9.