I had a print problem with 6.1 and panther...I could print from any app except 6.1..When I did, it acted like it went, but never printed (to HP1850)..After hacking around, including replacing fonts,I found this solution.
Went to HD > Library> Fonts....Get info>Ownership and Permissions. Changed all permissions to RW, and clicked on the "apply to enclosed items" button.
This fixed the printing problem. Not sure why, but some things are best left a mystery.