WD Backup Interferes With ITunes

As of the most recent update to ITunes for XP (, the playback of my music library is interrupted when WD Backup is running.  The interruptions last from 1 to 5 seconds, and are apparently random.  The interruptions stop immediately when I shut down WD Backup.  The WD Backup version is 4.00.5484.

I’m a newby here…any thoughts?  Thanks.