Here is what I had:

In the .css file I had this:

Code:
background-image: url('../header_images/rotate.php');
then I had a number of jpg's in the /includes/templates/<mytemplate>/header_images along with a rotate.php file (that I found out on the web when google searching) in that same directory that looked like this:

Code:
<?php
/*
  By Matt Mullenweg > http://photomatt.net
  Inspired by Dan Benjamin > http://hiveware.com/imagerotator.php
  Latest version always at:
  http://photomatt.net/scripts/randomimage
*/

// Make this the relative path to the images, like "../img" or "random/images/".
// If the images are in the same directory, leave it blank.
$folder = '';

// Space seperated list of extensions, you probably won't have to change this.
$exts = 'jpg jpeg png gif';

$files = array(); $i = -1; // Initialize some variables
if ('' == $folder) $folder = './';

$handle = opendir($folder);
$exts = explode(' ', $exts);
while (false !== ($file = readdir($handle))) {
  foreach($exts as $ext) { // for each extension check the extension
    if (preg_match('/\.'.$ext.'$/i', $file, $test)) { // faster than ereg, case insensitive
      $files[] = $file; // it's good
      ++$i;
      }
    }
  }
closedir($handle); // We're not using it anymore
mt_srand((double)microtime()*1000000); // seed for PHP < 4.2
$rand = mt_rand(0, $i); // $i was incremented as we went along

header('Location: '.$folder.$files[$rand]); // Voila!
?>
Everything was working great until I put on the Ultimate SEO Urls contribution and now my header won't show up. If I change the code in the .css file to this:
Everything was working great until I put on the Ultimate SEO Urls contribution and now my header won't show up. If I change the code in the .css file to this:

Code:
background-image: url('../header_images/picture.jpg');
The header works but it won't rotate obviously.

I am thinking it has something to do with the url being rewritten because of the rotate.php file reference but I can't figure it out.

Thanks for your help in advance.