Hi all. I've been using an ISA 2000 (+SP2 + FP1) proxy with basic authentication for the machines which are in the network BUT not in the windows domain.
It's working fine with Internet Explorer since it asks for the credentials with a popup screen.

My problem is that now I've to use an application that requires Microsoft ISA's security client (since it's using a non standard port). It's working on the machines which are in the domain using integrated authentication but in the machines which are not in the domain I get an authentication error and it isn't even asking for the credentials.

What should I do to force the clients to authenticate?

Thank you all in advance!