Voice key problems

Hi there

I am trying to collect voice key responses. Software is DirectRT2008.1.0.13 and hardware is a Mac Pro (running Windows XP) with an ASUS Xonar Essence STX PCI soundcard. We installed the sound card after not being able to get DirectRT to read input from other devices (USB and Firewire audio interfaces - the Mac Pro doesn't have a mic input). In all cases the problems are the same:

- I have confirmed in Control Panel that the desired audio device is selected for input

- I have confirmed using other software (Audacity) that the mic is actually providing sound input to the computer that I can record and play back just fine

- when I run Voice Response Setup I get a popup window Titled "Project1" that says "-1" and plays an error tone, then when I click OK it goes to the Voice Response setup window. If I run "monitor" I get no response even with the gain all the way up.

- When I access Sound Tools from the Voice Response Setup window, I get the following behavior:
Sound recorder - menu options show correct input device, but sound not recorded
Check Sound Levels: I get an error "There is a problem with your sound hardware. To install mixer devices go to Control Panel, click Printers and Other Hardware, the click Add Hardware. When I do this, Windows says everything is OK with my hardware.
DirectX Diagnostic tool: Nor warnings or errors listed.

Do you have any ideas what might fix this?

Thanks!
Aaron