I am having a problem including a file.

The script is executing here:
docroot/common/branch1/executing_script.php

The file I want to include is here:
docroot/common/branch2/desired_include.php

The include path on the server is :
include_path='.:/usr/services/vux/lib/php'

My include statement is:
include("../branch2/desired_include.php");

I have also tried:
include("./../branch2/desired_include.php");

Are relative paths not allowed?

Edit:

I've tried both methods on a second server and they work fine. Somebody's crippled include relative paths on the first server.