RewriteRule with scgi on Apache 2

Hi.
I am trying to run RubyOnRails with scgi on RedHat ES4.
I want to direct all access of “/” to index.html
I do have DirectoryIndex in httpd.conf.
But after I run RubyOnRails, the configuration stopped working.

I tried many things, but it doesn’t work.
Like:
RewriteRule ^$ index.html [QSA]
RewriteRule ^/$ /var/www/public/index.html [R]

If I access /index.html, everything works fine.

If I access /, it says “The page cannot be found”.
I don’t have scgi-bin or dispatch.scgi on my Linux ES4.
Is that normal?
It will be very helpful if somebody can provide a sample httpd.conf file
and

.htaccess file.
Thank you,