nslookup firewall config problem

["Robin Rowe" <rower@MovieEditor.com>]

My Linux box is behind an NT firewall. The Linux box is 192.168.1.2. The NT
box is 192.168.1.1. I want to access CVS on SourceForge, but cvs reports
"Unknown host" when I attempt pserver login.

Using nslookup also fails, on sourceforge.net or any name:

    *** Can't find server name for address 192.168.1.1: No information
    *** Default servers are not available

However, dig works without problem. Likewise, apt and my web browser (opera)
work fine.

What could be wrong with my Debian configuration that cvs and nslookup can't
resolve anything?

Thanks,

Robin