I have a studio using Sonar X1 and I'm considering converting to Pro Tools as I have PT MP9. I also have an MAudio Fastrack Ultra 8R USB connected unit. I can use the Fastrack Ultra 8R with both Sonar and Pro Tools.
When you are using a recording program you do not need to set any recording device in the Sound Panel. The recording program sets up the device for recording.
The first thing is to make sure you are installing the MAudio unit correctly. When I installed my MAudio unit, I ran the MAudio installation program, which also installed the MAudio Control Panel for the Fastrack Ultra 8R. I then connected the unit and it was detected and Installed by Windows. Once it is detected and installed correctly you can then use Pro Tools or whatever and set up the audio, in the recording program for your MAudio unit.
There is also an MAudio forum, for help with MAudio Devices: The Official M-Audio User Forums