changing default directoryindex with .htaccess

[coffeedemon]

I'm running a apache server on a win2kserver.

when i add .htaccess containing:

DirectoryIndex index.html index.php index.cgi index.pl default.htm

I get a 500 error.

I checked the httpd.conf file and it has

<IfModule mod_dir.c>
DirectoryIndex index.html index.php
</IfModule>

but for some reason it still lists the directory rather then index.php, index.html, etc.