When the Webcam is plugged into the USB port, it installs its own audio input driver for the onboard microphone.
When I connected the Webcam, it removed all of the input drivers within SONAR - the only input driver displayed was the Webcam mike). (Interestingly, it did not remove the drivers from within Cakewalk 9.03)
The solution I found to this was to go to SETTINGS/MULTIMEDIA/AUDIO and change the PREFFERED DEVICE within the RECORDING section to "USE ANY AVAILABLE". For some reason, the Logitech device assigned itself as the preffered device.
Hope that saves a few hair follicles for somebody out there.
