If you do not have Gnome installed it sounds like it would try to install all the dependencies for GTK. Since most of these dependencies are on your dvd (I assume it is free or powerpack), it could pay to have the cd/dvd mediums enabled and the disc in your drive. That is really the only thing I can think of that would make it download what seems a lot more than what would seem necessary. What version of Mandriva are you running, I assume 2008.1?
Second for your network trouble, this is pretty hard to diagnose, but have you tried to disable IPv6? Have you tried to tried to download the packages manually and installed them? (both gnutella and gnapster are part of the penguin liberation front's free pacakges, so you can browse to
ftp://mdk.linux.org.tw/pub/plf/mandr...elease/binary/ and go to the correct architecture for you and download the package manually and try to install it).