I've been trying out the available linux cam projects as well.
Are you using blender 2.77? or 2.78? Just installed blenderCAM with blender 2.78 and I'm getting an error related to setting machine work areas.
Edit: got it working on 2.78 (it didn't like my model). Definitely going to take a bit to learn, but it's immediately giving me better paths, faster than any other FOSS solution I've looked into.