GPO and MNC music contributions

Hi again all,
Here is something interesting that may shed some light on my problem. (although I have no idea what to do about it)
The Acoustica Recorder I downloaded (trial version) has a dialog box under "preferences" with a small box that says:
"Some sound cards do not support simultaneous recording and playback. This will not matter if you are playing sounds from another sound card". Below that statement is a "Test" button.
With GPO Studio NOT loaded, pressing the test button states "Sound card supports full duplex"
Opening GPO STudio and pressing the test button again states "Sound card FAILED full duplex test".
Closing GPO Studio and pressing the test button again, the message then reads "Sound card supports full duplex". So there is definitely something wrong only in GPO. Any ideas?
Thanks again,
Fred