First of all, I can only describe how it works for Mandrake, I'm not sure if it will work with Fedora, maybe a Fedora-guru can be of some assistance here.
Second, if you have an AMD 2800+ you are running the nForce2 chipset, this means you'll have to install another driver.
You can get it by clicking here:
after you have downloaded it get into a terminal and type:
followed by your root-password, this will give you complete controll.
go to the dir where you downloaded the nForce driver and type:
rpm --rebuild NVIDIA_nforce1.0-0261.src.rpm
a lot of info will pass your screen, just look for a line like:
go to this dir where you will find your new compiled nForce-driver
rpm -ivh NVIDIA_nforce......rpm
this will install the nForce-driver called nvnet
All that you have to do now is configure your network, don't know how to do this in Fedora.
NOTE For mandrake I had to install the kernel-source also, don't know if it is already installed in Fedora, maybe a Fedora-guru has the answer to this.