Do you have an index file (ie index.html, index.php)? If you have a designated landing page with a different name you'll have to tell the server you want that to load by default, or change its name (and any links going to that file). To tell the server that your landing page should be the one called home.php (as an example) you would need to edit/create .htaccess and add the following (without quotes): "DirectoryIndex home.php". Change home.php to match your file.
Were you previously having the domain show a directory listing?
If you did you will now need to edit/create .htaccess and add the following line (without quotes): "Options +Indexes". This is due to the directory listing being turned of by default for security.
If none of the above works, let me know and I'll investigate further.
