Index: wp-includes/class-snoopy.php
===================================================================
--- wp-includes/class-snoopy.php	(revision 5382)
+++ wp-includes/class-snoopy.php	(working copy)
@@ -796,7 +796,7 @@
 			$headers .= "User-Agent: ".$this->agent."\r\n";
 		if(!empty($this->host) && !isset($this->rawheaders['Host'])) {
 			$headers .= "Host: ".$this->host;
-			if(!empty($this->port))
+			if(!empty($this->port) && $this->port != 80)
 				$headers .= ":".$this->port;
 			$headers .= "\r\n";
 		}