Thanks for your comment Windell.
I was able to solve the issue (at least part way, I am not set up to test it thoroughly tonight) by adding the eiBot vendor and product id in my /lib/modules/3.6.11+/modules.usbmap file.
After I did that, plugging in the device led to the creation of the /dev/ttyACM0 node that had previously not been created by hotplug.
