How ever my error log gets filled with the following warning.
[20-Aug-2010 15:18:21] PHP Warning: session_start() [<a href='function.session-start'>function.session-start</a>]: Cannot send session cache limiter - headers already sent (output started at /home/user/public_html/site.org/inc/header.inc.php:12) in /home/user/public_html/site.org/data/index.php on line 23
It is not that big of a deal but since I custom code 90% of the stuff on my website I like to keep my error log clear. This way I can track my own problems with code.
I can tell you that I do not add any headers for any other script on the page.