Interesting workaround:
session_register("lastaction");
session_register("userip");
session_register("lines"); // etc etc
$HTTP_SESSION_VARS["xx"] = "Anything"; // this is the magic bit
Although xx isn't a registered session var, and doesn't get stored in
the session, it seems to stimulate PHP to update the session vars in the
file!
With that addition, my apps now work fine under 4.1.2
John