Vista - Less ASTC DTV Channel on my Vista MCE PC.

Hello Everyone.

I just build own Vista MCE PC. I installed Asus Digital + Analog PCI-e
Tuner.
I have Vista Home Preimum.

I set up MCE to watch digital TV (ATSC over the air channel). I am living
Los Angeles Area.

I can watch HD digital TV such as ABC channel 7-1 or any other channels no
problem.

However, no matter how I set, MCE can not detect sub channels such as 7-2,
7-3.
Within the MCE TV guide also does not show any sub channels.
It shows only XX-1 channels. No XX-2, XX-3 and so on.

I can watch those sub channel on regular HDTV.

I could add sub channels by manually from MCE set up pages. If I do that I
can watch normally.
However TV guide goes not show correct information for added sub channels.

Does anyone know how to show sub channels correctly?
or how to set up MCE (or TV guide) correctly?

T.I.A.
Matt