Additional note: the error.log shows this on the 404:

2014/05/23 11:11:24 [error] 25677#0: *5 "/etc/nginx/html/uri/index.html" is not found (2: No such file or directory), client: 127.0.0.1, server: , request: "GET /uri/ HTTP/1.1", host: "site.ordprofile01.example.net"