Problem installing ELGG on Rackspace cloud sites

Hi all,

I'm trying to install elgg 1.7.7 on Rackspace cloud sites, in subdirectory,

However, when I try to save my settings, I'm meeting 404 error (...elgg/engine/handlers/action_handler.php not found), ... is the absolute path to the elgg folder,

I also considered the problems with .htaccess, but since it is asking for the handler php, I think it's not .htaccess problem.

I think I cannot access the file because I only have permission in my web root,

Has anyone met this before, please help me to resolve this, I talked with the agent, but he doesn't seem to have experience with elgg installation