Image upload failures after server PHP update

[gsimon]

headers already sent by (output started at /home/shabonna/public_html/gs/plugins/sa_welcome.php:12) in /home/shabonna/public_html/gs/admin/inc/cookie_functions.php on line 23

The output (which triggers sending the html headers) is started by the bold bit. What is around line 12 of sa_welcome.php? Indeed, what is the contents of sa_welcome.php?

What is the full list of plugins installed (from the Plugins tab in admin backend)?

Thanks for the reply!  Answers to your questions are below.
-george

Contents of sa_welcome.php:
=========================  Begin sa_welcome.php ==================
<?php
/*
Plugin Name: sa_development
Description: Provides page generation times
Version: 0.1
Author: Shawn Alverson
Author URI: http://www.shawnalverson.com/

*/

$SA_PLUGIN_NAME = "sa_welcome";
$SA_PLUGINPATH = $SITEURL.'plugins/'.$SA_PLUGIN_ID;
$SA_URL = "http://tablatronix.com/getsimple-cms/";

# get correct id for plugin
$thisfile=basename(__FILE__, ".php");
$plugin_id = $thisfile;
$tab_name = $plugin_id; // can be unique

# register plugin
register_plugin(
$plugin_id,                  //Plugin id
$SA_PLUGIN_NAME,          //Plugin name
'0.1',                  //Plugin version
'Shawn Alverson',           //Plugin author
$SA_URL,                    //author website
'Adds page generation time to footer', //Plugin description
$tab_name,                //page type - on which admin tab to display
'tabcallout'              //main function (administration)
);

# debugLog(print_r($plugin_info,true));

add_action('nav-tab','createNavTab',array($tab_name,$plugin_id,'Welcome'));
add_action($tab_name.'-sidebar','createSideMenu',array('item_manager','Create a Litter','category'));
add_action($tab_name.'-sidebar','createSideMenu',array('item_manager','Add a Kitten','edit'));
add_action($tab_name.'-sidebar','createSideMenu',array('item_manager','View All Records','view'));

add_action('item_manager-sidebar','createSideMenu',array($plugin_id,'Back To Menu'));

function tabcallout(){
  echo '<h2>Welcome</h2>';
  echo '<h3>To Add a litter</h3>';
  echo '<p>First you must create a liter by clicking <b>Create a Litter</b> to the right, this is the category for kittens in the litter<br>
  Category names must be unique, and will show up on the site, I suggest you name them "Sire Dam Breed DOB" for consistency.</p><br>';
  
  echo '<h3>To Add a kitten to a litter</h3>';
  echo '<p>After you have created a category for the litter, click go <b>Back to Menu</b>, and click <b>Add a Kitten</b>. Kitten titles must be unique across all kittens. Choose a title that is unique for this kitten, the title is not shown on the site but is used to identify the record. A unique name might be <b>DOB #1</b> and so on. Then assign a category for this kitten, you will pick the litter category you just created.</p>
  <p>You can continue filling out information for this kitten. To add photos, click the red boxes and select a file, only select one file per image upload button.</p>
  <p>If you edit an existing kitten(by clicking its name in view all) and then change its title, upon saving, it will create a new record, effectively copying the kitten! You can use this to copy kittens while making only minor changes such as sex and #. You can overwrite images, and remove them by removing the image name that appears below the upload button. This is a bit awkward at this time.</p>';
  
  echo '<h3>To mark a kittens availability</h3>';  
  echo '<p>You can mark a kitten sold by editing it and checking the sold checkbox. Sold kittens will continue to show up on the site as SOLD.</p>';
  
  echo '<h3>To remove a kitten from listing</h3>';  
  echo '<p>It is not recommended to delete records from the system, unless it is erroneous. This way you can keep a historical record of kittens.</p>
  <p>To remove kittens and litters from the site listings, click the visibility flag on the relevant row for the kitten under view all. This will toggle a kittens visibility on the site. If all kittens in the litter are hidden, the litter will no longer show on the available kittens page.</p>';
  
}

function createlitter(){
  header('Location: admin/load.php?id=item_manager&category');
}

?>
=========================  End sa_welcome.php  ===================

========================= Installed Plugins ======================