Index: modules/node/node.module
===================================================================
RCS file: /cvs/drupal/drupal/modules/node/node.module,v
retrieving revision 1.1028
diff -u -p -r1.1028 node.module
--- modules/node/node.module	8 Mar 2009 04:25:04 -0000	1.1028
+++ modules/node/node.module	11 Mar 2009 06:22:01 -0000
@@ -1035,10 +1035,10 @@ function node_submit($node) {
 
   if (user_access('administer nodes')) {
     // Populate the "authored by" field.
-    if ($account = user_load(array('name' => $node->name))) {
+    if ($node->name && $account = user_load(array('name' => $node->name))) {
       $node->uid = $account->uid;
     }
-    else {
+    elseif (!isset($node->uid)) {
       $node->uid = 0;
     }
   }