When copying .cwp project files and their associated Audio folders over to an external drive for backup, somehow that process introduces random hash-distortion spots into each of the Audio folder files.
 
Anyone seen this before ?
 
I'm using Sonar X1 Producer on Windows 7 with a 64-bit OS, Intel Core i5 CPU.

How are you doing the copying? I never heard of anything like that before.

I'm doing a simple drag and drop copy over to a folder on an external drive.

How is the backup being tested? IOW, is the copy on the external drive copied back to the HD for playback or is the backup being played directly from the external drive?

Actually, I tried doing it both ways, thinking there might be some issue with latency going over the USB connection, but examination of the copied Audio folder files showed that all of them were affected with what I'm calling these 'hash distortions'.
The original files on the computer's internal drive are all clean and unaffected, which is why I believe the cause must somehow be related to the copying process.

Have you tried backing up to a different location on the HD instead of the external?

No, haven't tried that yet, but I will first thing tomorrow. I'll let you know...

This morning I was able to back up the Audio folder to another internal drive without problem. Then I found I was able to back up to another external USB drive (a Maxtor drive) without problem. So now I'm thinking the problem may be isolated to this one specific external drive (a Toshiba 1 TB drive).
I suppose I could go test out other external drives (Seagates, etc.), but I've never seen this kind of thing happen to audio files (.wav) before in 10 to 15 years of audio work.

Just guessing, but maybe there's a RAM cache in the hard drive and there's a problem with the RAM.

I have a Toshiba Canvio 2T External drive that I use to transfer between computer occasionally. 
I just tested an audio file buy opening it in Wave lab and all is good. I don't think this is a brand issue but must be something wrong with that drive for sure. Bad sectors ?, is it full?