TV Tuner in build 5536 (saa7134)

I previously ran vista public beta 2 and managed to get my TV Tuner card
(Compro DVB-T300, phillips saa7134) working in media center. It took alot of
trial and error with various different drivers found on the internet.

Now I have upgraded to build 5536, and no matter which driver I try I
haven't been able to get Media Center to detect my tuner card. The best
result I've had is to have the tuner.exe (I forget the real name) crash in
the background.

Does anyone have any idea how I can get my tuner to work, or has anyone
managed to get theirs working? I don't understand why it refuses to function
when it worked fine in an older build. Thx.