Index: includes/install.inc
===================================================================
RCS file: /cvs/drupal/drupal/includes/install.inc,v
retrieving revision 1.70
diff -u -p -r1.70 install.inc
--- includes/install.inc	20 Sep 2008 20:22:23 -0000	1.70
+++ includes/install.inc	26 Sep 2008 19:59:06 -0000
@@ -733,6 +733,11 @@ function drupal_install_mkdir($file, $ma
  *  TRUE/FALSE whether or not we were able to fix the file's permissions.
  */
 function drupal_install_fix_file($file, $mask, $message = TRUE) {
+  // We're doing a file_exists because a silly drupal_verify_install_file() calls this function without doing so. This may apply for other usages of this function, too.
+  if (!file_exists($file)) {
+    return FALSE;
+  }
+
   $mod = fileperms($file) & 0777;
   $masks = array(FILE_READABLE, FILE_WRITABLE, FILE_EXECUTABLE, FILE_NOT_READABLE, FILE_NOT_WRITABLE, FILE_NOT_EXECUTABLE);