[CentOS] Do i have to open port 631 for LAN printing

Hi, I have a Samsung printer(ML-2010) connect to my centos 4.2 machine by usb. I want to share this printer with 3 windowsXP mchines in my LAN. Although i have install driver for the printer on all machines, use samba to share the printer, from the windows machine i still have an error"access denied, can not connect to printer" or something similar. In Security Level, i have checked "trusted device: eth0, sit0" , is port 631 automatically open? How do i know that my problem is not caused by the blocked port? Hope anyone can help Thai ________________________________________________________________________ Check Out the new free AIM(R) Mail -- 2 GB of storage and industry-leading spam and email virus protection.