Index: soap_server.module
===================================================================
--- soap_server.module  (revision 633)
+++ soap_server.module  (working copy)
@@ -87,6 +87,7 @@
 function soap_server_server() {
   // Load soap library
   if (@include_once(realpath(soap_server_nusoap_path()))) {
+    drupal_set_header('Content-Type: text/xml; charset=utf-8');
     // Launch the server
     return soap_server();
   }