problem reading sessions

I have just recently set up PHP on my Win2K laptop and I have just found out that I can't read sessions. As far as I can tell the session file is being created, but PHP doesn't seem to be able to get any data into it. Here is what the session file looks like: !sess_user|!blah| The two PHP files look like this: test_session1.php <? $blah = "good"; session_start(); session_register("blah"); ?> test_session2.php <? session_start(); echo session_is_registered("blah") . "<br>"; echo session_encode(). "<br>"; echo isset($HTTP_SESSION_VARS) . "<br>"; echo sizeof($HTTP_SESSION_VARS) . "<br>"; echo $blah; ?> For the second PHP page the ouput I get is: - true for the 'session is registered' function - the string that is found in the session file (listed above) - true for the 'isset' function - size of zero - The warning: 'Warning: Undefined variable: blah ' Does anybody know why I would not be able to read these variables? thanks, alastair