Thanks, Tachikoma, but that wasn't the problem.
I did finally get zbar running.
Usage instructions.
So what I do now is open a terminal and type
zbarcam > ~/Desktop/BTCaddress.txtZbar will scan the barcode. You'll know it has grabbed it when you see the thin green box around the QR Code on your monitor. Once it grabs the QRCode, it puts it into a text file on the desktop. Close the video preview window to exit zbarcam.
Then double click the text file, cut & paste the address into the Bitcoin client.