disable_functions on virtual hosts?

I'd like to disable certain functions for a particular virtual host, and leave them as is for all the rest. The usual way to do this would be to include something like: php_admin_value disable_functions system,exec in the virtual host's configuration block. However, this doesn't work, and scripts are still able to use the disabled functions. phpinfo() shows "system,exec" under "local value" for disable_functions, which would seem to indicate that the configuration is correct, even though it doesn't work. I made a little experiment and added those functions to php.ini's disable_function directive, and in this case it works perfectly, and the specified functions are disabled. I'm wondering if I'm missing something here, or is this a known problem with PHP? This is PHP 4.0.6 running on OpenBSD 2.9 with Apache 1.3.19. I guess I can live without disabling those functions on one particular virtualhost, but I'd sleep better knowing they are disabled. Thanks in advance! - Daniel Manrique