Compass error: Webkit only supports pixels for start and end stops of radial gradients

I have a problem in my Backbone application. I am using sass and compass.

When I try to create an application, I get this error:

Running compass: dev task (compass) warning Webkit only supports pixels for the start and end stops of radial gradients. Received: 70%

My background image (texture image file) is also compiled to 100%, which makes all of my textures look large and grainy.

What do I need to do so that I don't get this error?

Thank!