Vista - No sound from Live TV in Media Center

Sound works fine in everything else.
Here is my configuration:
MB GIGABYTE GA-EP35-DS3R 775 P35
CPU INTEL|C2D E8400 3G 775 45N
VGA XFX PVT88PYSF4 8800GT 512M
CASE ANTEC|SONATA PLUS 550
TV TUNER HAUPPAUGE|1128 HVR-1800
HD 500G|WD 7K 16M SATA2 WD5000AAKS
DVD BURN SAMSUNG|SH-S203B
S/W MS WIN VISTA 32BT HMPRE 1P DVD
CPUCOOLER|ARCTIC P4|ACFZ7-PRO
OCZ SLI-Ready Edition 2GB (2 x 1GB)
240-Pin DDR2 SDRAM DDR2 1066 (PC2 8500)
Dual Channel Kit Desktop Memory Model
OCZ2N1066SR2GK
Creative Sound Blaster SB0570 Audigy SE 7.1 Channels
PCI Interface Sound Card

Hi, lbrende, and welcome to the forums.

Since you have the same tuner as I have in my system, I need to know a couple of things - are you using digital cable or analog, and is it connected to the correct one?

Also, if you remove the cable from the back of the computer and plug into either a TV or a tuner elsewhere, do you get sound?

I am using a simple antenna. The only instance where sound does not work is live TV in Media Center. I read on one Microsoft posting that Vista defaults to some muted ASC or something audio stream and that Vista developers seemed to feel they have no ability or power to correct this.
I did have sound at one time. I cannot go back to that time though, since I reinstalled Vista a while back.
Thanks,
David

OK, so we're sure that the live TV is actually getting sound to the tuner card. Hmmm. I have no issues, but I use cable not an antenna - but I suppose it should not matter....

Check out the drivers for the tuner - perhaps something has happened to change something there? Cause you and I have the same tuner, and mine works flawlessly in both Vista x64 and Windows 7 x64.

Have you installed any codec packs recently, or conversely have you tried un-installing a codec pack?

Not that I know of. What is a Codec pack?

If you don't know what a codec pack is, then chances are you haven't installed one

A Codec is any technology that compresses or decompresses data. A Codec pack contains many different codecs essential to view many different video formats. They also contain audio codecs.

ie Windows media Player won't play High Def .mkv files by default, adding a Codec Pack which contains the correct codec , will allow you to display the image.

Since it seems likely that it's not a codec issue, have you tried checking the volume mixer while media Centre is running to see if it's unmuted?

(start and then minimize media center / right-click on the sound icon in the taskbar and open volume mixer. The media center volume slider only appears when Media Center is running)

I have Vista 32 Home Premium. There is no slider, but the indicators show sound is unmuted and shows a number in a box as the level of volume. Video clips and recordings done when the player had sound work without flaws.
Just no sound on Live TV. Window sounds work in Media Center.

So I had sound at one time, just can't figure this out. Is it possible to reinstall media center from my Vista install disk? I guess I would have to set everything up again.

Unfortunately to re-install media Center, you have to re-install the entire OS

Does your tuner have any proprietary software that may have a volume control of it's own?

No, I used media center. When I could not get sound, I installed "WinTV" from Hauppage, it does have sound on live TV, but the screen size is small and not as many features as Media Center.