I tried the Vantec Nexstar CX with WD10EARS EHD (others had no problems with this enclosure and EHD) on the 6131 receiver and it does not recognize the drive. I tried on three different 6131 and none of them works.
I then moved the EHD to two 9241 receivers and they both recognized the drive immediately and asked me if I wanted to format the drive.
I tried another EHD which is currently being used to store all my PC data on the 6131 and immediately recognized it and requested me to format the drive.
Any help is greatly appreciated. Thanks in advance.