I purchased a 42" Vizio flat panel HDTV recently, and I hooked up the HDMI from my Windows 7 box (I'd been using DVI and RCA before without this issue). Since then, the volume while watching TV will vary wildly over 10 second or so lengths of time. I'll hardly be able to hear it, so I'll raise the volume, and then it will start to get louder and louder, so I'll have to turn the volume back down again - it seems like I'm adjusting it about every 2-3 minutes.

I've tried enabling the "Normalize volume" option (whatever it's actually called) in Media Center, but it doesn't seem to make any difference.

Has anybody else had volume control problems? Even if you haven't, can somebody recommend a good volume normalizer to use on W7?

This is an odd issue. Are you sure it isn't just the volume changing during commercials? That is normal, and yes very annoying.

Ah - it turns out that my TV has some "SRS enhancement" feature that was enabled by default. It ought to have been named "Constantl vary volume in an unpredictible way when it's least expected".

I suspected nothing was wrong with the HDMI - thanks for your help!