Linux user group folder permissions

I have a basic linux file permissions question:

I have a folder named test:

$ ls -la
drwxr-xr-x  5 root root    4096 2010-10-25 17:11 .

drwxr-xr-x 17 root root    4096 2010-10-25 16:53 ..
drw-rwS---  3 root codedev 4096 2010-10-25 17:11 test

In this folder (test) I want all users that are members of the group codedev to have read and write access, even to those files (inside test) that other users has created.

I have a testuser:

$ groups testuser 
testuser : testuser codedev

Why can't the user testuser cd into the directory test? How should I do the make this work?

Answer

In order to cd to a directory the user needs execute permission on the directory too, either by dint of ownership, or at the group, or world/other level.