Issue with Brain Jr. and optical encoder

I am having some issues getting the optical encoder from a CDJ1000mkii to respond correctly with the livid Brain Jr. The optical encoder I am using has 4 pins. 

1. Ground

2. VCC

3. enc1

4. enc2

I have wired Ground and VCC to the ground and +5v on the usb. The closed to getting this to work I have gotten is plugging enc2, and enc1 into PCB Label (1-) and (3-) on the brain. It seems to work when the encoder is turned slowly, but as soon as I turn the encoder fast the data it sends is erroneous. Is there a known issue with the Jr not responding to fast encoder movements? Is there a fix for this issue? All help is appreciated. 

Thank you!

Matthew