No, there is no problem with the website. The problem here is you cannot directly link to a file in your published folder. It will work for a while; but when the session times out, the link will become invalid.
To get a permanent link to a published file, please follow this instructions:
Click on "Publish" on top of the Homepage; click on "Manage My Published Folder", Click on the published folder in the list; You should see this: "This folder is accessible at: http://www.drivehq.com/file/ShowFolder.aspx?G=1&shareID=###, No logon is required to access this folder. " This link is the permanent link to the published folder. Click on the link to open the folder, and click on each file to open the file. You can find the "permanent link to the file" by copying the Download link (and remove forceDownload=true)