That error is what would happen if you selected the same camera in both instances of iCamSource. The model name may be the same, but Windows actually generates a unique identifier for each camera that is connected, so it shouldn't be confusing the two cameras.
Make sure that you are picking a different video source in each instance of iCamSource. For example, in the first iCamSource, select the first entry in the Video list and in the second iCamSource, select the second entry in the Video list. I'm assuming the identical camera name shows up twice in the iCamSource Video drop-down list.