[Resolved] Dumb problem with session_start()

[njm]

I'm building a new site, and have used sessions before in other projects, but I can't work out what I'm doing wrong this time

<?
session_start();
header("Cache-control: private"); // IE6 bug fix

require_once("fn.php");
require_once("boilerplate.php");
write_top();
echo '<div id="body">';
write_left();
echo '<div id="main">';

if (isset($_GET['submit']))
	{
		select_crawl($_GET['crawlid']);
	}
echo '</div>';
?>

This page has a form on it, with the action set to itself. Clicking the form gives me the dreaded "Cannot send session cache limiter" error, pointing at line 2. But I can't see any obvious errors. Other pages on the same site have the same problem. What am I doing wrong, that I wasn't other times? Anybody help?

Thanks, njm

[sid]

did you make sure you dont have any whitespaces at the beginning of the files?

[njm]

Sid,

I know there shouldn't be any whitespace, and I didn't think there was. After a bit more digging around, I eventually found the solution here and
here

Regards, njm