Posting the url to you site very much helps identify the problem (as is often the case).
Wholly is right on the money. From looking at your site, it is obvious that it is using WordPress and that another .,htaccess file (in your "main" directory - /home/r_diaz/dmculturalservicesltd.com/) is in place providing rewrite rules. (note the "pretty" urls on your links).
The unexpected behavior you are getting when trying to navigate to the url http://dmculturalservicesltd.com/t_munson/ is the result of these rules. WordPress "traps" urls that are not part of it's system and this is what is happening to you. The .htaccess file in the dmculturalservices.com directory affects all directories beneath it if not modified by and an .htaccess file in that directory. As it is, the .htaccess file in t_munson directory never gets read, because the "higher" .htaccess file is intercepting the request and rewriting the url.
It is very similar to the problem you would experience if you navigate to the url http://dmculturalservicesltd.com/stats/ and there is a great guide to resolving this on the DreamHost Wiki.
Take a look at the DreamHost Wiki Article on Making Stats Available with .htaccess for a discussion this situation and an example of how to fix it for a "stats" sub-directory. You need to make the same "fix", but substitute "t_munson" for "stats' in the examples.