diff -uprN markup_snippets_orig/markup_snippets.js markup_snippets/markup_snippets.js
--- markup_snippets_orig/markup_snippets.js	1970-01-01 01:00:00.000000000 +0100
+++ markup_snippets/markup_snippets.js	2010-01-09 01:58:46.511586150 +0100
@@ -0,0 +1,49 @@
+// $Id$
+
+/*
+ * Attach AJAX/AHAH event handlers for Wysiwyg integration.
+ *
+ * This code takes care of Wysiwyg integration in D6.
+ * Wysiwyg module needs to be able to detach any attached editor before the
+ * AJAX request is made or it cannot be re-attached afterwards.
+ * Drupal 6 does not have detach behaviors so we need to manually call
+ * Drupal.wysiwygDetach(). Wysiwyg's own behavior won't be able to
+ * re-attach the editor either because the context doesn't include the
+ * format selector so we call Drupal.wysiwygAttach() manually too.
+ *
+ * @param context
+ *   A DOM element, supplied by Drupal.attachBehaviors().
+ *
+ * This code is based on Drupal.behaviors.attachWysiwyg from Wysiwyg module. 
+ * @see Drupal.behaviors.attachWysiwyg in Wysiwyg module.
+ */
+Drupal.behaviors.markup_snippets = function (context) {
+  // Add a global AJAX listener for attaching/detaching Wysiwyg module.
+  $('#edit-body-wrapper:not(.markup-snippets-processed)', context).each(function () {
+    $(this).addClass('markup-snippets-processed').bind('ajaxSend', function (event, XMLHttpRequest, ajaxOptions) {
+      // Detach the Wysiwyg module if this is our request.
+      if (ajaxOptions.url == '/markup_snippets/js') {
+        $('.wysiwyg-processed', $(this).parent()).each(function () {
+          var $this = $(this);
+          $this.removeClass('wysiwyg-processed');
+          if (($this.is(':input') && $this.is(':checked')) || $this.is('div')) {
+            var params = Drupal.wysiwyg.getParams(this);
+            Drupal.wysiwygDetach($this.parent(), params);
+          }
+        });
+      }
+    }).bind('ajaxComplete', function (event, XMLHttpRequest, ajaxOptions) {
+      // Re-attach the Wysiwyg module if this is our response.
+      if (ajaxOptions.url == '/markup_snippets/js') {
+        $('.wysiwyg:not(.wysiwyg-processed)', $(this).parent()).each(function () {
+          var $this = $(this);
+          $this.addClass('wysiwyg-processed');
+          if (($this.is(':input') && $this.is(':checked')) || $this.is('div')) {
+            var params = Drupal.wysiwyg.getParams(this);
+            Drupal.wysiwygAttach($this.parent(), params);
+          }
+        });
+      }
+    });
+  });
+}
diff -uprN markup_snippets_orig/markup_snippets.module markup_snippets/markup_snippets.module
--- markup_snippets_orig/markup_snippets.module	2010-01-09 01:59:38.451586675 +0100
+++ markup_snippets/markup_snippets.module	2010-01-09 01:58:46.511586150 +0100
@@ -14,6 +14,11 @@ function markup_snippets_form_alter(&$fo
   
   // make sure we're on a node form and user has permission to use snippets
   if ($form['#id'] == 'node-form' && user_access('use snippets')) {
+    // Include the Wysiwyg module integration.
+    if (module_exists('wysiwyg')) {
+      drupal_add_js(drupal_get_path('module', 'markup_snippets') . '/markup_snippets.js');
+    }
+
     // enforce caching for ahah
     $form['#cache'] = TRUE;
     
@@ -21,11 +26,11 @@ function markup_snippets_form_alter(&$fo
     $type = node_get_types('type', $form['#node']);
     
     // set up a new fieldset above the node body field
-    $form['body_field']['markup_snippets'] = array(
+    $form['markup_snippets'] = array(
       '#type' => 'fieldset',
       '#title' => t('Mark-up Snippets'),
       '#description' => t('Load saved snippets or save the contents of the current !body_label field.', array('!body_label' => $type->body_label)),
-      '#weight' => -100,
+      '#weight' => -1,
       '#collapsible' => TRUE,
       '#collapsed' => FALSE,
     );
@@ -47,7 +52,7 @@ function markup_snippets_form_alter(&$fo
     }
     
     // render the actual form field
-    $form['body_field']['markup_snippets']['markup_snippets_select'] = array(
+    $form['markup_snippets']['markup_snippets_select'] = array(
       '#type' => 'select',
       '#title' => t('Select a snippet to use'),
       '#description' => $description,
@@ -61,15 +66,31 @@ function markup_snippets_form_alter(&$fo
         'event' => 'change',
       ),
     );
-    
+
+    // During AHAH requests, markuo_snippets_select will have a value > 0.
+    if ($form_state['values']['markup_snippets_select'] > 0) {
+      // Change body value here to keep cache synced with the rendered form.
+      $mid = $form_state['values']['markup_snippets_select'];
+      $snippets = markup_snippets_get_snippets(array(), TRUE, $mid);
+      $form['body_field']['body']['#default_value'] = $snippets[$mid]['snippet'];
+    }
+
     // we need a field for naming our snippet
-    $form['body_field']['markup_snippets']['markup_snippets_name'] = array(
+    $form['markup_snippets']['markup_snippets_name'] = array(
       '#type' => 'textfield',
       '#title' => t('Enter a name to save the current snippet'),
       '#size' => 30,
       '#description' => t('If you enter a name in this box then the contents of the !body_label field will be saved as a snippet when you click Save.', array('!body_label' => $type->body_label))
     );
-    
+
+    // We need a custom submit handler for AHAH, must use a button for that,
+    // but it can have #access => FALSE so the user won't see it.
+    $form['markup_snippets']['markup_snippets_submit'] = array(
+      '#type' => 'submit',
+      '#access' => FALSE,
+      '#value' => 'submit_snippet',
+      '#submit' => array('markup_snippets_get_snippets_submit'),
+    );
   }
 }
 
@@ -391,6 +412,17 @@ function markup_snippets_get_snippets($s
   return $snippets;
 }
 
+/*
+ * Custom submit handler for AHAH requests.
+ */
+function markup_snippets_get_snippets_submit($form, &$form_state) {
+  $node = $form_state['values'];
+  unset($form_state['submit_handlers']);
+  form_execute_handlers('submit', $form, $form_state);
+  $form_state['node'] = $node;
+  $form_state['rebuild'] = TRUE;
+}
+
 /**
  * Implementation of ahah callback for node form.
  */
@@ -407,10 +439,7 @@ function markup_snippets_js() {
   // causes an error because the node gets locked.
   
   // Preparing to retrieve form from cache
-  // Old line:
-  // $form_state = array('storage' => NULL, 'submitted' => FALSE);
-  // Our replacement:
-  $form_state = array('storage' => NULL, 'rebuild' => TRUE);
+  $form_state = array('storage' => NULL, 'submitted' => FALSE);
   $form_build_id = $_POST['form_build_id'];
   
   // Retrieve the form from the cache
@@ -430,27 +459,14 @@ function markup_snippets_js() {
   // CUSTOM CODE STARTS HERE
   
   // Now we have the latest $form, with the changes made by our
-  // AHAH enabled field - we can now build our mark-up to return
-  
-  // get the node type info we need for our body field
-  $node = $form['#node'];
-  $type = node_get_types('type', $node);
-  
-  // load the snippet from the posted data
-  $mid = $form_state['post']['markup_snippets_select'];
-  $snippet = markup_snippets_get_snippets(array(), TRUE, $mid);
-  
-  // build the returned mark-up
-  // we are mimicking the output of the node_get_body() function
-  $output = '';
-  $output .= '<label for="edit-body">' . check_plain($type->body_label) . ': </label>';
-  $output .= '<div class="resizeable-textarea"><span>';
-  $output .= '<textarea class="form-textarea resizable textarea-processed" id="edit-body" name="body" rows="20" cols="60">';
-  // switch the body for our snippet
-  $output .= $snippet[$mid]['snippet'];
-  $output .= '</textarea>';
-  $output .= '</span></div>';
-  
+  // AHAH enabled field - we can now render our mark-up to return
+ 
+  $changed_field = $form['body_field']['body'];
+  $output = drupal_render($changed_field);
+  // Strip the wrapper as only its contents will be replaced.
+  $output = preg_replace('/^<div.*?class="form-item".*?id="[^"]*?-wrapper".*?>/', '', $output);
+  $output = preg_replace('/<\/div>\s*$/', '', $output);
+
   // ALL DONE
 
   // Final rendering callback - send our mark-up back to the div we