We got a brand new Mac with Snow Leopard at work. Can't make Safari/Firefox resolve names. Works just fine for internal resources through finder, but even going to my intranet site by its alias is no go. Can reach it by IP address though.
So far, Apple tech support is stumped by this (I am currently at 3rd level technical support).
As an added note if you ever wanted to hear Bob Dylan played through the worst speaker ever made, call Apple and have them put you on hold.