Sorry for the inconvenience. It was reported by a couple users that in some rare situation, the backup info file can become corrupted. Usually it is related with a crash, an unexpected system shut-down, or network disconnects when the backup task is being performed.
We have improved the way to handle those exceptions. The latest version should be much more reliable on this respect. The latest version has a Build number of 248. You can find the build number by clicking on top-left corner of the Online Backup application window, and select "About DriveHQ Online Backup".
To work around the current problem, please re-create the backup tasks using exactly the same info. (same name, same source folders). Your new backup tasks will reconnect to the existing backup sets on DriveHQ.com. If you forgot your previous backup task info, you can use DriveHQ FileManager to browse folders in "\DriveHQData\DriveHQ WWWBackup\Data". It should give you some info on the backup task names and which folders/files you've backed up before.