I am using Windows 8.1 (64-Bit) with a Western Digital My Book Live NAS and I have the same problem.
RecImg Manager sees the network shares on my other Windows machines, but will not see the shares on the NAS.
I have used the command line to map a drive as instructed, but still the share is not visible in RecImg Manager.
Has this been resolved? Is there a solution or should I un-install RecImg Manager?