Your DNS does not appear to be properly set-up to resolve that name to point at your DH webspace.
Take a look at your whois and DNS Report
Your NS records at the parent servers are:
ns1.elsewhere.net. [188.8.131.52] [TTL=172800] [AU]
ns1.realsurf.com. [184.108.40.206] [TTL=172800] [AU]
ns2.realsurf.com. [220.127.116.11] [TTL=172800] [AU]
[These were obtained from g.gtld-servers.net]
Your NS records at your nameservers are:
ns2.realsurf.com. [18.104.22.168] [TTL=86400]
ns1.realsurf.com. [22.214.171.124] [TTL=86400]
Which explains why you can see your directories in your DH space via ftp, but not via http. If you are hosting a domain on DH you need to set your DNS records to use DH nameservers (ns1.dream.com, ns2.dreamhost.com, and ns3.dreamhost.com). Normally, this is done at your registrar.
If, however, you are hosting realsurf.com on another host, you will need to be more creative to host rincon.realsurf.com on DH and have DNS work. There are many threads about this situation on the forums which explain this process, including this recent thread on pointing DNS at subdomains