What you are doing is making a new kernel. Just add it to the others. Are you using lilo?
That is the same cpu AMD Sempron 2800+ that I am using on that box. make the new kernel and install it;
find the agp stuff and follow mine, then
make install (this will install the kernel, set up the symbolic link to vmlinuz, just look in /boot and you should see it then update lilo
my motherboard will support 64bit but I use the 32bit sempron
If you are using the 64bit?
P.S. If i use the "vmlinuz" bootloader doesn't load it, it gives back an error...
I need to use the "bzImage" (arch/i386/boot/bzImage), it's correctly?
Did you run make make modules_install make install?
To see if it is there
After you install the kernel did you run lilo?
I just like to install kernels this way. the next one I install will be vmlinuz and the one before becomes vmlinuz.old
And It can be confusing, the .config file is in your kernel, I have always rerun make menuconfig and let it create the new file, I guess you could just edit it but I have never done it that way.
Also here is my xorg.conf and kernel .config
This is on a laptop with a;
01:05.0 VGA compatible controller: ATI Technologies Inc ATI Radeon XPRESS 200M 5955 (PCIE)