Index: wp-admin/includes/media.php
===================================================================
--- wp-admin/includes/media.php	(revision 9672)
+++ wp-admin/includes/media.php	(working copy)
@@ -173,10 +173,13 @@
  */
 function media_handle_upload($file_id, $post_id, $post_data = array()) {
 	$overrides = array('test_form'=>false);
-	
-	$post = get_post($post_id);
-	$time = $post->post_date_gmt;
 
+	$time = current_time('mysql', true);
+	if ( $post = get_post($post_id) ) {
+		if ( '0000-00-00 00:00:00' != $post->post_date_gmt )
+			$time = $post->post_date_gmt;
+	}
+
 	$file = wp_handle_upload($_FILES[$file_id], $overrides, $time);
 
 	if ( isset($file['error']) )