I found this page where they are having a similar problem
http://www.phpbuilder.com/board/showthread.php?t=10310794
Your error seems to say that configuration.php on line 1 is sending headers before the session can start causing an error. One thing they said is a blank line or space might cause it. If you open your configuration.php file in a text editor like Notepad what is the first line in the file? Is it a space? You should see this on the first line with no space before it;
<?php
Someone else said you could set the session cache to …