--- matrix-6.x-1.3/matrix.module	2009-02-22 08:48:26.000000000 +0000
+++ matrix/matrix.module	2009-03-11 10:29:16.000000000 +0000
@@ -288,6 +288,10 @@ function matrix_field_formatter_info() {
  */
 function theme_matrix_formatter_default($element) {
   $field_info = $element['#node']->$element['#field_name'];
+  if (!is_array($field_info['cols_header'] || !is_array($field_info['data']))) {
+    return;
+  }
+
   $header = $field_info['cols_header'];
   array_unshift($header, '');