Compass Sprites Throwing Errors When Compiling

Question

When compiling my css in compass with a sprite, I get the following errors:

error scss/app.scss (Line 107 of icons/*.png: Mixin sprites doesn't have an argument named $separator.)

The funny thing is, the sprite image is being made, but the css is throwing the error. I set up following Foundation's instructions.

Below is my setup.

code in app.scss:

@import "compass/utilities/sprites";
@import "icons/*.png";
@include all-icons-sprites;

Folder Structure

+ www
  + sass
    - app.scss
  + images
    + icons
      - thumbsup.png
  + config.rb

config.rb

http_path = "/"
css_dir = "stylesheets"
sass_dir = "scss"
images_dir = "images"

Thanks in advance!

Jay