Brief Background:
i have recently purchased a Nova t 500 DVB-T Tuner card, and planned to use this in conjunction with Media Portal on Windows 7 x64 Professional. got it all set up following step by step a well known guide over at GamerHub (http://forums.gamerhub.co.nz/showthread.php?t=47646). Basically, i had 2 different H.264 codecs installed, AAC and AC3 audio codecs and Matrosa Haali splitter installed. Within MediaPortal, i had audio but no sound, on every freeview channel
At that point i tracked down a WinTV disk and installed WinTV 7, and found i had the same issue. In the advanced settings menu i have no H.264 codecs able to be selected. i am very confused, hopefully some of you guys are able to help out :)
system specs as per signature, below is a pic of WinTVs advanced settings.

my plan is to get this card working with WinTV first, and then get mediaportal (or other suitable media centre application) running.
(currently using UHF aerial on roof, scans and finds all freeview channels fine)
Thanks in Advance
Jonty
EDIT: Location: Christchurch, using Sugarloaf Tower