Why can’t I publish to my new domain?

I just purchased a new domain and setup my current ISP (dial-up) to host it. Now when I attempt to publish my site, I get the following message.

“The server couldn’t log you on, because its only authentication scheme is NTLM and you are connecting to it via a proxy server. Try adding the server to the Exceptions box in the Tools/Options/Proxy Settings/Advanced dialog, or request the server administrator to enable another authentication scheme.
”

I spoke with the ISP and they say that they don’t have a problem publishing to it.

Does anyone have an idea of how I can resolve this issue?
– Win98 2nd-edition
– MS Frontpage2000
– Going through a proxy server (MS SBS4.5)

Thanks,
Byron