Routing and PHP scripts, not loading the index.php

I’m in the process of changing a PHP site to ROR. I think this is a
routing problem.

Going to:

http://www.mycoolsite.com/

doesn’t load up the index.php … I have index.php in the DirectoryIndex
directive in Apache2.

http://www.mycoolsite.com/index.php

Works however, if you go to any other urls that have no file name
specified (since index.php is default)

http://www.mycoolsite.com/account/

Also same problem.

I’ve looked and googled for the past few hours, I can’t seem to figure
out how to go about this. Has anybody done something like this? or
should I just change all my php pages to specify index.php ??