SEPM Blocking Shared USB Printers in Workgroup

I recently installed SEPM on a workgroup and since then there have been issues printing to shared USB printers.

User1 will print to User2's shared USB printer and User2 will get a notification that SEP will block User1's IP address for 600 seconds. I checked the log files and the rule it falls under is "Block all other IP traffic and log"

How would I resolve this? According to the users it only happens intermittently because User1 is able to sometimes get print jobs through. I need to be able to have anyone that has the shared printer installed to be able to print to it.

All machines are running Windows 7 and are on the same wokgroup.