Site connection Problem

I have set up ftp accounts for my students at school. On my teacher machine,
using dreamweaver, I can connect to all of them. However, when we try to
connect on the student machines, dreamweaver says 'the site is down or not
currently accepting connections'. I have checked all the settings in the Site
dialogue and cannot find anything wrong. Any ideas?

Does the teacher machine have different permissions on teh network than the student machines?? I would get a network admin involved.