5.0.594 Sharing Printer

A search of the forums returned some questions similar to mine but no answers.

I have 2 XPs on workgroup with a printer installed on LPT1 on one box. Using the free Home Avast this allowed both machines to print. With 5.0.594, I have to change the firewall from “Medium” to “Low” in order for the second machine to access the printer. Is there a way to set up a rule to allow this communication with the firewall in “Medium” so both machines can use the printer? Is the port for the printer Port 35/TCP?

Is this just something we shouldn’t be doing?