Printer Sharing over a network is one bugaboo of OS X. There is no easy solution, short of waiting for Jaguar. Supposedly it will be fixed in 10.2. You can sometimes get it to work by running Printer Sharing in Classic. I found that to be hit or miss, and often sleep kills it. I needed to boot into OS 9, set up Printer Sharing and test it, then reboot into OS X, start Classic, double-check that the settings for Printer Sharing stayed active, and then pray. Wish I had a better solution for you, but hopefully this will all go away in a few weeks.