Roamio Expansion Drive

I'm having some trouble with my Roamio and my expansion drive. The expansion drive is a Western Digital 500 MB that used to be attached to my TiVo HD. I was able to connect it to my Roamio initially but have been having problems since. Several programs that were recorded after the expansion drive was installed are not working. The Roamio stopped recognizing the expansion drive and it's taken many attempts to get it to connect. I finally gave up and removed the expansion drive.

Is this a Roamio problem or an expansion drive problem?