$PHP_SELF Problems

Hi, When I try to execute form code that looks like this: <FORM METHOD="post" ACTION="<?php echo $php_self ?>"> [...] </FORM>, I get this error in Netscape Navigator/Comunicator Mac/PC version 4.5: "Method Not Allowed The requested method POST is not allowed for the URL /wsm/index.html." It only delivers this message if the browser is NN. IE works fine. If I change the $php_self variable inside the form tag to the actual location of the php script, it seems to work, but other problems seem to arise and it seems like a bad way of doing things. Any ideas? Thanks, Beau