Acronis not detecting WD My Book

Hi, i have a Windows 7 PC with a Western Digital My Book 2TB connected via USB2.0 and i am evaluating Acronis True Image 2015. The issue i am having is that Acronis True Image does not detect the My Book when clicking on the "Select destination" icon/circle which is seen on the Acronis backup screen. If i unplug and reconnect the My Book and then open Acronis it will show. This is not ideal as i do not want to have to do this every time i want to backup.
Please note i am not experiencing any issues with seeing and accessing the drive in windows explorer.