I have 24 assorted Macs in my two classrooms. 14 eMacs (rev 1) and 10 Minis (rev 1). All of the computers can get online and download files. Three of the Minis and 6 of the eMacs can access secure (https sites with no problems, as well as downloading Apple software updates. The rest cannot do wither of these. They were all cloned from one of the machines that does get online and to secure sites and downloads software updates. They all go through the same DHCP server (with sequential addresses), they all have the same OS and apps (from the clone--10.4.2, Safari 2.0). I double checked all settings in control panels to make sure the cloning was identical, and it was. I'm really perplexed, since I'm usually able to solve most of my problems quickly, but Network issues have never been on my list of important things to learn. We only have a part-time (2 days/week) tech for a 200 teacher high school, so I thought I might get some faster help here. Thanks!