Index: wp-includes/class-IXR.php
===================================================================
--- wp-includes/class-IXR.php	(revision 26916)
+++ wp-includes/class-IXR.php	(working copy)
@@ -629,6 +629,10 @@
             if (!$this->path) {
                 $this->path = '/';
             }
+
+            if ( ! empty( $bits['query'] ) ) {
+                $this->path .= '?' . $bits['query'];
+            }
         } else {
             $this->server = $server;
             $this->path = $path;
Index: wp-includes/class-wp-http-ixr-client.php
===================================================================
--- wp-includes/class-wp-http-ixr-client.php	(revision 26916)
+++ wp-includes/class-wp-http-ixr-client.php	(working copy)
@@ -20,6 +20,9 @@
 			// Make absolutely sure we have a path
 			if ( ! $this->path )
 				$this->path = '/';
+				
+			if ( ! empty( $bits['query'] ) )
+				$this->path .= '?' . $bits['query'];
 		} else {
 			$this->scheme = 'http';
 			$this->server = $server;