This error message will be displayed when a song uses up more audio blocks on disk than its length would imply.
There are two possible scenarios; one (theoretical) cause would be that a power failure occurred right after pressing the 'stop' button on the HD24 recorder. This would however be extremely unlikely to occur. One other possible cause may be that an audio block was incorrectly assigned to the end of the song. This may have been done by our recovery service to allow for enough silence to fit the song length. No data loss is caused by this process.
Power outages can be prevented with a UPS. The latter cause can usually not be prevented.
If the situation was caused by a power outage, proceed with the procedure to recover from data loss due to power failures. If the situation was caused by our recovery service, it should still be possible to backup the song from one disk to another. After this, you can safely run the HD Scan utility on the HD24 recorder to remedy the situation.