Mp3's are distorted while running backup

Gday

AMD Phenon II x 4 965
4GB DDR3
Gigabyte GA-MA77OT-UD3P
Nvidia GeForce 9800GT
and new Creative X-Fi Ectreme Audio
Vista Ultimate 32 Bit

Ever since I have had the updated version of Acronis True Image Home 2011, whenever a scheduled backup runs, my MP3's get all "choppy", to the point where I have to turn them off.

As a rule I run the backups when I am in bed, so I didn't notice this problem when it first occurred.

I had been using the onboard sound prior to this, and thought maybe the backup was "overloading" it, so I went and bought a separate sound card (see above).

The problem didn't stop, so I made sure I had all the latest drivers installed, sound video etc.

I found my Nvidia card was behind on one update, so naturally I updated it, ran a backup, and no sound distortion.

Wooo hooo or so I thought, it appears that was the one and only backup where my sound was not choppy.

I have run :-

Malwarebytes' Anti-Malware 1.46
www.malwarebytes.org

Database version: 4052

Windows 6.0.6002 Service Pack 2
Internet Explorer 8.0.6001.18999

20/12/2010 10:41:57 AM
mbam-log-2010-12-20 (10-41-57).txt

Scan type: Quick scan
Objects scanned: 120636
Time elapsed: 6 minute(s), 1 second(s)

Memory Processes Infected: 0
Memory Modules Infected: 0
Registry Keys Infected: 0
Registry Values Infected: 0
Registry Data Items Infected: 0
Folders Infected: 0
Files Infected: 0

Memory Processes Infected:
(No malicious items detected)

Memory Modules Infected:
(No malicious items detected)

Registry Keys Infected:
(No malicious items detected)

Registry Values Infected:
(No malicious items detected)

Registry Data Items Infected:
(No malicious items detected)

So I know there are no nasties causing this problem, but it has me stumped as to why when I use Acronis to do a system backup this occurs.

I have defragged, scanned all of my drives for any errors (time consuming when you have 2 x 1TB hard drives and a 2 TB hard drive)