Thank you for using our service. We are very sorry for the inconvenience.
We had just experienced an unusual amount of heavy network traffic (seems to be an attack) and we have fixed the problem. The FTP service is working mostly fine now.
In the meantime, the web-based service and DriveHQ FileManager 4.0 / Online Backup 4.0 are all working fine.
There are still some minor issues related with certain files become inaccessible, which we are working on it and should be fixed within 24 hours.