Has this ever worked on your system with Mountain Lion? Looking at the vendor site the software is listed as running on 10.5 and 10.6. Nothing after that is mentioned for this device.
One thing to try make sure the camera is powered off before attaching the USB cable from it to the Mac. Once the cable is attached turn it on and see if that makes any difference.
I don't know as it's a new school computer--had a PC before. I have a macbook pro and macbook air at home, but have never connected a camera or projector to them. I tried turning off the doc camera prior to connecting the cable as you suggested, but to no avail--"camera not found." Any other suggestions? I am desperate .
I'm afraid that the camera is either defective or else will not work with the current version of the Mac OS, Mountain Lion.
As I wrote when I went to the Elmo site and looked at the support page for that camera the software was only listed as running on 10.5 and 10.6. I would suggest you try and contact the manufacture/developer to find out if the model you have will work on 10.8.
Sorry I can't be of more help