To set the remote so that Volume and Mute operate the TV even if you are in AUX or CABLE mode, follow the procedure under "Changing Volume Lock", "Locking Volume Control to TV or AUX Mode" (press and hold Setup until the light flashes, enter 993, press TV).
I have a Scientific Atlantic 8300 HDDVR, the silver remote with the red select button.
I have no problems controlling the volume on my tv after pressing TV
I have no problems operating my DVR after I hit AUX
But when I am on AUX, if I press the volume key, the volue does not change but I get the white display at the top of the screen that shows me the slider moves. I am able to mute the box, just not raise and lower the volume.
I'm so tired of switching back and forth for the volume.