First, you have to set the sample rate to 48000. Then a new panel will appear in the configuration dialog which has a button named "ASIO Panel". Press this button, and a new dialog will appear in which you will be able to set the buffer size. If this doesn't work, I can send you a little program which will can open on its on the Audigy ASIO Control Panel. I'm using the APS ASIO Drivers and I have a SB Live!, not Audigy, so the problem could be related to the drivers.