world editor doesn't work

What steps will reproduce the problem?
1. Copy gumworld project to a directory
2. Copy gw2_skeleton files into new directory created in 1 above
3. > chmod 755 world_editor.py
4. > ./world_editor.py

What is the expected output? What do you see instead?
Expected to see some sort of working program start up with some kind of editor.

Actual:
pymunk not found: proceeding without
gummworld2 v0.3.0 loading...
tiledtmxloader loading ... 
DEBUG:tiledtmxloader:tiledtmxloader.tiledtmxloader loading ...
tiledtmxloader loaded: 0.014416s 
gummworld2 v0.3.0 loaded
Traceback (most recent call last):
  File "./world_editor.py", line 154, in <module>
    from gummworld2 import (
ImportError: cannot import name Map
stephen@stephen-MCP7A:~/gaming-projects/scrollers/my-first-scroller$ 

What version of Python, pygame, and Gummworld2 are you using? On what
operating system?

Python 2.7, and 
1.9.1release-0ubuntu4
latest download, as of a few minutes ago:

Please provide any additional information below.

Original issue reported on code.google.com by steveo98...@gmail.com on 12 Feb 2012 at 11:59

Merged into: #13

google-code-export / gummworld2

world editor doesn't work #18