Fatal error message appears when i chang the permissions of the include folders

I INSTALLED THE ZENCART SOFTWARE AND WAS ABLE TO SEE THE NEW SHOPPING CART BUT IT HAD A MESSAGE AT THE TOP TO CHANGE THE INCLUDE PERMISSIONS TO 644 0R 444

I CHANGED THE PERMISSIONS TO THE /INCLUDE AND ADMIN/INCLUDE FOLDERS TO 644 AND GOT THE FOLLOWING FATAL ERROR MESSAGE:

Fatal error: main() [function.require]: Failed opening required 'includes/application_top.php' (include_path='.:/usr/lib/php') in /homepages/29/d276827773/htdocs/shop/index.php on line 26

WHAT SHOULD I DO KNOW THAT THE SITE IS NOT SHOWING AT:

http://navcfcs.com/shop/

the permissions for the FOLDERS should be 755

notice that its the
includes/configure.php and the admin/includes/configure.php FILES that need to be 644 or 444 depending on the server setup