Failed to read from sector 976.773.167 of hard disk

Hi there,
I have this error message when I want to make a Backup with True Image 2013 by Acronis. This error appears to all my partitions. It says all the time that the data cannot be read. All my partitions work and can anyone help me to make a Backup ? Why I have this kind of error ?
Thanks !

Failed to read data from the disk. Failed to read from sector ‘976.773.167’ of hard disk ‘3’. Try to repeat the operation. If the error persists, check the disk using Check Disk Utility and create a backup of the disk. Failed to read the snapshot manager drive. (0×1000D7) Unknown status (0×9).
