diff -Nurw Examples/php/callback/example_wrap.cxx Examples/php/callback.good/example_wrap.cxx
--- Examples/php/callback/example_wrap.cxx	2009-06-20 11:53:16.000000000 +0200
+++ Examples/php/callback.good/example_wrap.cxx	2009-06-20 11:50:53.000000000 +0200
@@ -1149,6 +1149,8 @@
 }
 
 void SwigDirector_Callback::run(std::string foo) {
+  zval *args[1];
+  zval arg1;
   if (!swig_self) {
     SWIG_PHP_Error(E_ERROR, "this pointer is NULL");
   }
@@ -1156,8 +1158,11 @@
   
   ZVAL_STRING(&funcname, (char *)"run", 0);
   
+  args[0] = &arg1;
+  ZVAL_STRINGL(&arg1, const_cast<char*>(foo.data()), foo.size(), 1);
+
   call_user_function(EG(function_table), &swig_self, &funcname,
-    &retval, 0, NULL TSRMLS_CC);
+    &retval, 1, args TSRMLS_CC);
   return;
 fail:
   zend_error(SWIG_ErrorCode(),"%s",SWIG_ErrorMsg());