I had this same problem recently. I found it was not the disks but the disk drive that was the problem. In my case it had not been fitted correctly so the disks were not going in far enough. To prove a point if you take one of the suspect disks to another computer and it reads OK, you on the right track.
I found the drive was set too far back in the case, I brought it forward, never had the problem again.
No promises, but it worked for me.
Hope this helps
Regards
The Doc