After using the following code to start a second instance of p910nd, I cannot seem to print any documents:
/usr/sbin/p910nd -b -f /dev/usb/lp1 1
Using MAC OS X 10.7, I can connect to the second printer (Canon MX320) and print a test page. When I try to print anything from an app (tried Word and Preview), it refuses to do so. The print spool status changes to "Connected to Printer - Printing," yet nothing happens.