I've been banging my head against the wall over an error reported in some PHP code I've been writing. For some reason the session would be trashed on the server and on next page load I'd get "Node no longer exists" when I tried to open the session.
It turns out that you can't take a response from a SimpleXML object and store it in a session. You'd think that if you could type "echo $myxml->thisnode" and get a string that it's really a string, but PHP automatically typecasts and converts as needed - except in the case of storing in a session variable.
There's an easy solution. Use explicit typecasting when trying to store an XML result string in a $_SESSION variable:
$_SESSION['myinteger'] = (int)$myxml->myinteger; $_SESSION['mystring'] = (string)$myxml->mystring;