JMFS Blues :-(

I'm trying to to upgrade a Premiere 4 WD A-V 500gb drive with a 2tb WD Green drive. JMFS is giving a "no TiVo drive detected" message. I pulled the original 500gb drive from the Premiere and put it directly in the USB-3 dock.There are two curious issues going on.The first being that the device boot screen won't come up when the original 500gb stock drive is in the USB dock.I use a flash drive to boot JMFS.After I remove the stock drive for a moment the device boot choice screen comes up and I select the flash drive and quickly put the stock drive back in the USB dock but when JMFS loads it still does not detect the original TiVo drive. The second curious issue in all this is that I just finished a SUCCESSFUL upgrade of my other Premiere 4 a couple hours ago using the exact same method -same USB docks, same flash drive to boot JMFS. The ONLY difference is that both the original 500gb stock drive and the target expanded drive are Seagate Pipeline HD2 drives, not WD Green drives. I know that I've been long-winded here but can anyone out there offer any help? I'd sure appreciate it !! :-)