dvb-t card in vista causing hairloss...mine!

[k.jacko]

Ok, the dealio is:

vista x86
some crazy dvb-t card, which worked fine once.
After an almost complete system rebuild changing mobo, gfx card, ram and hdd. Updated vista to sp1, updated mobo drivers and bios.
Installed tv card, ran vmce; it took about an hour to finish scanning and only picked up 9 channels.
I have a freeview aerial on the roof with a loftbox splitting the signal to each of 4 bedrooms. PC in another bedroom with a different dvb-t card works fine. Another bedroom with tv/freeview box works fine.
The coax cable in the problematic bedroom works fine and gives excellent picture quality when plugged into a portable tv, so we know the cable/signal is fine.
So why the bugger won't it pick up more channels?
If anyone reading this is in the Nottingham area, i'm using the Waltham transmitter, which is what i've always done. Anyone know if there is a better one to try. I have 6 choices in the menu, but at about an hour each scan it will takes me ages to try all of them.
All drivers for the tv card work fine (supposedly). Yet when i try to go into 'live tv' it says 'no signal'. WTF????
From memory the first time i set it up last march time, i don't recall it asking me to setup either one or both of the tuners on the card. I only ever remember seeing one previously (could be wrong though). It shows them as BDA tuners, so i assume the most appropriate drivers are installed for vista. Not tried just scanning one channel since the rebuild.

Please help if you can, this pc is really driving me nuts, its just one problem after another!!

Thanks