Failed to read data from the disk

My laptop has a SSD and IDE drive. Acronis is setup with 2 jobs, one for the SSD and one for the IDE. Today, the IDE backed up fine. However, when backing up the SSD, Acronis came back with Failed to read data from the disk. The full error message is:

"Failed to read from sector '447.840.848' of hard disk '1'. Try to repeat the operation. If the error persiss, check the disk using Check Disk Utility and creat a backup of the disk. Failed to read the snapshot. (0x10C45A)  Unknown status. (0x9)  The request could not be performed because of an I/O device error (0xFFF0)"

Disk 1 refers to the IDE drive. But, since I was backing up the SSD drive, I ran a chkdsk on the SSD instead. It came back clean. So, I ran chkdsk on the external harddrive where the backup is stored. It was clean. I even ran a chkdsk on the IDE drive. Everything came back clean.

I selected to ignore all the error messages and let Acronis continue with the backup. I did see the the size of the new backup is smaller than the size of the previous backups. I then ran the backup again and it had the same Failed to read data error.

What I can do to fix this?

Thanks!