Win32/HTTP_SESSION_VARS problem

Hello, I'm running PHP 4.0.2 as an isapi dll under IIS 5.0. Here's my situation: // firstpage.php <?php

      session_register("foo");
      $foo = "foo_initial_value";
      header("Location: secondpage.php");

?> // end firstpage.php // secondpage.php <?php

      session_start();

      // no problem here; the if condition evaluates to 'true'
      if(session_registered("foo")) {

          // BUT this next line prints nothing if register_globals=off
          print($HTTP_SESSION_VARS["foo"]);
      }

?> // end secondpage.php If register_globals=off, session_register() does not seem to do its job. If I switch it on, run the code (which then prints the expected value), then switch it back off, change the value of $foo (e.g., $foo="foo_new_value" in firstpage.php), and then re-run the code, the value printed is still "foo_initial_value". The changed value is not registered. What might I be doing wrong? Or is this a bug? Thanks in advance, Mikah Azurin