The generated XML is now valid and it seems to work.

include/salmon.php

@@ -66,8 +66,6 @@ function get_salmon_key($uri,$keyhash) {
 
 function slapper($owner,$url,$slap) {
 
-	logger('slapper called for '.$url.'. Data: ' . $slap);
-
 	// does contact have a salmon endpoint?
 
 	if(! strlen($url))
@@ -97,6 +95,8 @@ EOT;
 
 	$slap = str_replace('<entry>',$namespaces,$slap);
 
+	logger('slapper called for '.$url.'. Data: ' . $slap);
+
 	// create a magic envelope
 
 	$data      = base64url_encode($slap);