Vista - Subwoofer Present setting

Hope this is the right place for this. I have a Soiund Blaster Audigy 2
Platinum. I HAVE installed Creative's Drivers for Vista Beta 2 -

here's my issue:

When I choose "quadriphonic" From the Play Control Volume properties, the
"Subwoofer present" choice is greyed out. Is nayone else experienceing this?
In addition - with the "quad" choice chosen - I am only getting sound on my
front two speakers and when I run the "test" fron the Test button - the test
sounds meant to come out of the rear speakers is emanating from the front.

Is anyone else experinecing this?

Thanks in advance

George