Index: wp-settings.php
===================================================================
--- wp-settings.php	(revision 11574)
+++ wp-settings.php	(working copy)
@@ -60,8 +60,8 @@
 if ( ! isset($blog_id) )
 	$blog_id = 1;
 
-// Fix for IIS, which doesn't set REQUEST_URI
-if ( empty( $_SERVER['REQUEST_URI'] ) ) {
+// Fix for IIS when running with PHP ISAPI
+if ( (strpos($_SERVER['SERVER_SOFTWARE'], 'Microsoft-IIS') !== false && php_sapi_name() != 'cgi-fcgi') || empty( $_SERVER['REQUEST_URI'] ) ) {
 
 	// IIS Mod-Rewrite
 	if (isset($_SERVER['HTTP_X_ORIGINAL_URL'])) {