My Living room Tivo HD is showing massive breakup (as in unwatchable) on just 3 or 4 channels. The other Tivo HD in the home office pulls those channels in just fine. Before I try to deal with RCN's (lack of) Support staff, I figured I'd post here and get some opinions. The THD in question was put in service in '08 and has the 500gig My DVR Expander, and my fear is that one or both of the drives is going south. Is there a quick check I can make to figure this out?