Daryl,
9 times out of 10, anytime you see that headers error, it is because of "white space" before or between php tags BEFORE the output of your page's html.
In other words if you had this, it would cause an error (notice the space between the php tags:
<?php
a bunch of code here and there
?>
<?php some more code ?>
Make sure all your pre-html PHP looks like this:
<?php
a bunch of code here and there
?>
<?php some more code ?>
Make sure there are no lines... you could even bring the start of the next PHP tag right after the close of the last one. This is where I would start first making sure there are no possible spaces between PHP tags or the beginning of the file... if it still gives the headers error, then we know to look elsewhere.
Best regards,
Brian