rss feed path

I’ve seen a couple of other folks with this issue and have tried what worked for them but cant get mine to work..
When I follow the path to the rss feed, I get an ‘500 internal server error’. If I change my permalink back to the default blank, my rss feed link changes to something like : http://ponderethereal.com/blog/wp/wp-rss.php but gets the same 500 error.
My permalink is this : /index.php/%post_id%/
The path WP creates for my feed is : http://ponderethereal.com/blog/wp/feed/rss/
My htaccess is this :
RewriteEngine On
RewriteBase /blog/wp/
RewriteRule ^index.php/category/(.*)/(feed|rdf|rss|rss2|atom)/?$ /blog/wp/wp-feed.php?category_name=$1&feed=$2 [QSA]
RewriteRule ^index.php/category/?(.*) /blog/wp/index.php?category_name=$1 [QSA]
RewriteRule ^index.php/author/(.*)/(feed|rdf|rss|rss2|atom)/?$ /blog/wp/wp-feed.php?author_name=$1&feed=$2 [QSA]
RewriteRule ^index.php/author/?(.*) /blog/wp/index.php?author_name=$1 [QSA]
RewriteRule ^index.php/([0-9]+)?/?([0-9]+)?/?$ /blog/wp/index.php?p=$1&page=$2 [QSA]
RewriteRule ^index.php/([0-9]+)/(feed|rdf|rss|rss2|atom)/?$ /blog/wp/wp-feed.php?p=$1&feed=$2 [QSA]
RewriteRule ^index.php/([0-9]+)/trackback/?$ /blog/wp/wp-trackback.php?p=$1 [QSA]
RewriteRule ^feed/?([_0-9a-z-]+)?/?$ /blog/wp/wp-feed.php?feed=$1 [QSA]
RewriteRule ^comments/feed/?([_0-9a-z-]+)?/?$ /blog/wp/wp-feed.php?feed=$1&withcomments=1 [QSA]
Any help would be GREATLY appreciated. 🙂