5 month-old Roamio Plus, 2 year-old Vizio TV (M470VSE), remote cleaned twice with isopropanol only, no obstructions to IR sensors on TV, surge protected power supply (exterior ground wired to home service panel), Vizio remote still works fine Our Roamio remote worked fine for 4 months. Then its Volume up/down toggle started to fail intermittently followed by intermittent function of Mute button. Now neither functions at all. All other buttons function perfectly. What I've tried: 1st- Software reset of remote TV code (tried all three codes for Vizio), followed menu commands explicitly twice (6 attempts). Remote's red LED lit up promptly (as expected) as I followed instructions. Found two of three codes will allow power button, channel toggle and numerical buttons to work on Vizio. However, neither of these two codes allowed volume or mute control. 2nd- Removed & reinstalled batteries, repeated code reset... still no volume/mute operation. 3rd-Software reset of remote to "default settings" by following directions involving amber LED and "thumbs down" button. 4th- Repeated 2nd (see above) 5th- Cycled power (10 second interrupt) on both Roamio and Vizio 6th- Repeated 1st (see above) Still no love... how is this possible? It can't be the Vizio, as its remote still controls the mute and volume. Must I purchase a new Roamio remote? And... why should I have to? It should be covered under warranty. I'm certain sludge isn't obstructing buttons or IR transmission. Any thoughts on how I should proceed, or am I doomed to keeping two remotes on the table?