Index: ubercart_disable_tax.diff
===================================================================
Index: uc_order/uc_order.order_pane.inc
===================================================================
--- uc_order/uc_order.order_pane.inc	(revision 96)
+++ uc_order/uc_order.order_pane.inc	(working copy)
@@ -483,17 +483,28 @@
       return $output;
 
     case 'edit-process':
+      $log = array();
       if (is_array($arg1['line_items'])) {
         foreach ($arg1['line_items'] as $line) {
           if (is_numeric($line['li_id']) && intval($line['li_id']) > 0) {
             uc_order_update_line_item($line['li_id'], $line['title'], $line['amount']);
+            $log[] = t("Line Item ID " . $line['li_id'] . ", " . $line['title'] . " changed to " . $line['amount'] . '.');
           }
         }
       }
-      if (intval($arg1['li_delete_id']) > 0) {
+      if (intval($arg1['li_delete_id']) > 0) { 
+        $line_item = uc_order_get_line_item($arg1['li_delete_id']);
         uc_order_delete_line_item($arg1['li_delete_id']);
+        $log[] = t('Line item id ' . $arg1['li_delete_id'] . ' was deleted.');
+        if($line_item->type == 'tax'){
+          $order = uc_order_load($arg1['order_id']);
+          $order->data['taxes_disabled'] = TRUE;
+          db_query("UPDATE {uc_orders} SET data = '%s' WHERE order_id = %d", serialize($order->data), $order->order_id);
+          $order = uc_order_load($arg1['order_id']);
+        }
         drupal_set_message(t('Line item removed.'));
       }
+      uc_order_log_changes($arg1['order_id'], $log);
       return;
 
     case 'edit-ops':
Index: uc_order/uc_order.line_item.inc
===================================================================
--- uc_order/uc_order.line_item.inc	(revision 96)
+++ uc_order/uc_order.line_item.inc	(working copy)
@@ -137,6 +137,14 @@
 }
 
 /**
+ * Return line item by ID
+ */
+function uc_order_get_line_item($id){
+  $result = db_query("SELECT * FROM {uc_order_line_items} WHERE line_item_id = %d", $id);
+  return db_fetch_object($result);
+}
+
+/**
  * Add a line item to an order.
  */
 function uc_order_line_item_add($order_id, $type, $title, $amount, $weight = NULL, $data = NULL) {
Index: uc_order/uc_order.admin.inc
===================================================================
--- uc_order/uc_order.admin.inc	(revision 98)
+++ uc_order/uc_order.admin.inc	(working copy)
@@ -1249,14 +1249,17 @@
       }
     }
   }
-
+  
   // Load line items again, since some may have been updated by the form.
   $order->line_items = uc_order_load_line_items($order, TRUE);
-
+  
   // Merge it with the defaultish line items.
   $order->line_items = array_merge($order->line_items, uc_order_load_line_items($order, FALSE));
   usort($order->line_items, 'uc_weight_sort');
-
+  
+  //Merge w/ stored order data in case something has changed in the database.
+  $order->data = array_merge($order->data, uc_order_get_data($order->order_id));
+  
   if (variable_get('uc_order_logging', TRUE)) {
     uc_order_log_changes($order->order_id, $log);
   }
Index: uc_order/uc_order.module
===================================================================
--- uc_order/uc_order.module	(revision 98)
+++ uc_order/uc_order.module	(working copy)
@@ -1123,6 +1123,7 @@
   }
 
   uc_order_module_invoke('save', $order, NULL);
+  return TRUE;
 }
 
 /**
@@ -1942,3 +1943,15 @@
 
   return $can_delete;
 }
+
+/**
+
+ * Return Data values for an order
+ */
+function uc_order_get_data($order_id, $leave_serialized = FALSE){
+  $result = db_result(db_query("SELECT data FROM {uc_orders} WHERE order_id = %d", $order_id));
+  if($leave_serialized){
+    return $result;
+  }
+  return unserialize($result);
+}
\ No newline at end of file
Index: uc_taxes/uc_taxes.module
===================================================================
--- uc_taxes/uc_taxes.module	(revision 96)
+++ uc_taxes/uc_taxes.module	(working copy)
@@ -159,54 +159,57 @@
 function uc_taxes_order($op, $arg1, $arg2) {
   switch ($op) {
     case 'save':
-      $changes = array();
-      $callback = _line_item_data('tax', 'callback');
-      $line_items = $callback('load', $arg1);
-      $context = array(
-        'revision' => 'formatted',
-        'type' => 'line_item',
-        'subject' => array(
-          'order' => $arg1,
-        ),
-      );
-      if (is_array($arg1->line_items)) {
-        //drupal_set_message('<pre>'. var_export($arg1->line_items, TRUE) .'</pre>');
-        foreach ($arg1->line_items as $i => $line) {
-          if ($line['type'] == 'tax') {
-            $delete = TRUE;
-            foreach ($line_items as $id => $new_line) {
-              if ($new_line['title'] == $line['title']) {
-                if ($new_line['amount'] != $line['amount']) {
-                  $context['subject']['line_item'] = $new_line;
-                  uc_order_update_line_item($line['line_item_id'], $new_line['title'], $new_line['amount'], $new_line['data']);
-                  $arg1->line_items[$i]['amount'] = $new_line['amount'];
-                  $changes[] = t('Changed %title to %amount.', array('%amount' => uc_price($new_line['amount'], $context), '%title' => $new_line['title']));
+      $order_data = uc_order_get_data($arg1->order_id);
+      if(!isset($order_data['taxes_disabled']) || !$order_data['taxes_disabled']){
+        $changes = array();
+        $callback = _line_item_data('tax', 'callback');
+        $line_items = $callback('load', $arg1);
+        $context = array(
+          'revision' => 'formatted',
+          'type' => 'line_item',
+          'subject' => array(
+            'order' => $arg1,
+          ),
+        );
+        if (is_array($arg1->line_items)) {
+          //drupal_set_message('<pre>'. var_export($arg1->line_items, TRUE) .'</pre>');
+          foreach ($arg1->line_items as $i => $line) {
+            if ($line['type'] == 'tax') {
+              $delete = TRUE;
+              foreach ($line_items as $id => $new_line) {
+                if ($new_line['title'] == $line['title']) {
+                  if ($new_line['amount'] != $line['amount']) {
+                    $context['subject']['line_item'] = $new_line;
+                    uc_order_update_line_item($line['line_item_id'], $new_line['title'], $new_line['amount'], $new_line['data']);
+                    $arg1->line_items[$i]['amount'] = $new_line['amount'];
+                    $changes[] = t('Changed %title to %amount.', array('%amount' => uc_price($new_line['amount'], $context), '%title' => $new_line['title']));
+                  }
+                  unset($line_items[$id]);
+                  $delete = FALSE;
+                  break;
                 }
-                unset($line_items[$id]);
-                $delete = FALSE;
-                break;
               }
+              if ($delete) {
+                uc_order_delete_line_item($line['line_item_id']);
+                unset($arg1->line_items[$i]);
+                $changes[] = t('Removed %title.', array('%title' => $line['title']));
+              }
             }
-            if ($delete) {
-              uc_order_delete_line_item($line['line_item_id']);
-              unset($arg1->line_items[$i]);
-              $changes[] = t('Removed %title.', array('%title' => $line['title']));
-            }
           }
         }
-      }
-      if (is_array($line_items)) {
-        foreach ($line_items as $line) {
-          uc_order_line_item_add($arg1->order_id, $line['id'], $line['title'], $line['amount'], $line['weight'], $line['data']);
-          $line['type'] = 'tax';
-          $arg1->line_items[] = $line;
-          $context['subject']['line_item'] = $line;
-          $changes[] = t('Added %amount for %title.', array('%amount' => uc_price($line['amount'], $context), '%title' => $line['title']));
+        if (is_array($line_items)) {
+          foreach ($line_items as $line) {
+            uc_order_line_item_add($arg1->order_id, $line['id'], $line['title'], $line['amount'], $line['weight'], $line['data']);
+            $line['type'] = 'tax';
+            $arg1->line_items[] = $line;
+            $context['subject']['line_item'] = $line;
+            $changes[] = t('Added %amount for %title.', array('%amount' => uc_price($line['amount'], $context), '%title' => $line['title']));
+          }
         }
+        if (count($changes)) {
+          uc_order_log_changes($arg1->order_id, $changes);
+        }
       }
-      if (count($changes)) {
-        uc_order_log_changes($arg1->order_id, $changes);
-      }
     break;
   }
 }