IIS 5.0 Multiple Virtual Servers Problem

I have setup a Windows 2000 Server with IIS 5.0 running FrontPage Server Extensions to host sites for some of our students. I wanted to be able to give them their own FTP and web sites for practice. I set up the NIC in the OS with multiple IP addresses. Then I setup a couple of sites to test with. I am using the Default Web and FTP sites (which work fine), but the test sites are having problems. I can FTP into the test sites with no problem, but, when I try to either view web pages or publish to the sites using FrontPage 2000, it says the site doesn’t exist. I have comed over the permissions of the sites and the folders on the server. I HAVE permissions. Any Ideas?