have printer added to localhost:631 not printable from remote computers only local ones

[Joeseph Modhal]

have printer added to localhost:631. not printable from remote computers.    the print server itself prints just fine.  anything remote it wont do.  i'm using ipp ipp://192.168.1.75:631/printers/HP_LaserJet_1018.  i dont have any ports open for cups not sure if they are required.  have done fresh installations of ubuntu gutsy on both the print server and remote computer.  i have tried to restart the print server on both computers.  still no go.  am getting a "HP_LaserJet_1018 at 192.168.1.75 may not be connected" error message in my print notification.  am also getting these error messages

E [19/Jan/2008:15:00:14 -0600] cupsdAuthorize: Local authentication certificate not found!
E [19/Jan/2008:15:00:14 -0600] cupsdAuthorize: Local authentication certificate not found!

in /var/log/cups error_log file

please help

thank you