Error: Failed opening ... by include on linux suse 6.4

I have php4 (as modul) with apache (ssl), and include files didn´t work.

I get this message:
Warning: Failed opening 'localhost/armin/demo.php' for inclusion
(include_path='') in /var/www/htdocs/armin/test.php on line 6

Setting the include_path in /etc/php.ini didn´t help.

In php3 there is no problem with include. Is there a diffeent between
php3 and php4 or is this a bug?

Thanks for tips

Armin Matthaei