I am having the same problem with similar hardware:
AMD XP 1700+
SiS 730 host
eVGA GeForce4 MX 440
The only way I can get the nvidia driver to work is by setting NvAGP to 0, as in this thread:
In any other AGP-enabled configuration, the system freezes shortly after X (KDE or Gnome) is loaded. Oddly, the mouse still moves but does not click. Must hard reboot.
The nv driver works OK, but with poorer performance. Even with AGP disabled, nvtv crashes when I try to turn the TV-view on, which is the reason I bought this card in the first place. Sucks to be me - help appreciated.