Welcome to the Virgin Media Community, I'm really sorry to learn about the problems you've been experiencing with your TV service lately.
I've been able to locate your account and take a closer look at this from our end for you, we're not detecting any issues from our end at the moment though.
How have you got the TiVo boxes connected, are you using any surround sound systems or are you plugged straight to the TV with a HDMI cable? Can you also check the audio settings on the set top boxes to see what they're set to please?
You can find this by selecting Help & Settings on the Home menu, then Settings and Audio.
Look forward to hearing from you and getting to the bottom of this problem
I had a similar problem where the sound was not registering on some channels, and sometimes it did. I was getting over this by unplugging the HDMI cable and plugging it back in, but as you can imagine it was an absolute pain.
I booked an an enginner visit doh changed the TiVo box, and now everything sems good
The audio is set to Dolby on both boxes, one is also connected to a home theatre system but it's a separate connection (not a pass-through). I'm puzzled why it's happening on both the stb's and why it started about the same time, fairly recently. It's also not consistent, sometimes it happens every few seconds, sometimes every couple of minutes, sometimes not at all, so I have no way to check what the hell's going on!
Unfortunately a whole load of VM customers are enjoying this new 'un-documented feature' kindly added by VM (over six weeks ago now) in their last TiVo software update. See the links below for the whole story...