OK, i'm pretty new to using Linux. So i install Mandrake 10.0 on the following hardware:

XP 2500
512 dual ch. pc3200
80 gig hd
9600se agp card
nforce2 ultra mobo
winxp pro dual boot

i've tried other disto's of linux before so i knew that i would have to tweak a few things, but this is getting stupid.

I have tried everything to get the freakin ati drivers to actually work. No matter what i do, fglrxinfo will ALWAYS display MESA drivers when all is said and done. its stupid. i've tried the ati directions, i've tried all the threads i could find on this message board, i've even tried rebuilding a kernel according to some directions i found through google...but nothing works. i get no errors while installing and it seems like it worked fine, but as i said, no 3d support. glxgears runs with a BLISTERING 135 fps ...weee.

i'm a stones throw away from just sticking with winblows xp unless i can get this fixed. any suggestions? i have the rpm files for ati's 3.11.1 and 3.12.0 drivers.

Im having this exact same problem with an nforce2 and radeon, im also a newbie... anyone out their care to help?

I know i har my problems too with this config (the only difference is that I don't have nforce2 but a kt400 mobo).
It happened the same, glxinfo reported me as OpenGL renderer MESA. I am using ATI 3.7.6 (fglrx-4.3.0-3.7.6.i386.rpm). I didn't try to use the ATI internal AGP driver so I use MDK's agpgart.o.
Try this:
[root]# ldconfig -v | grep libgl
It will report what libs are in use and that contain OpenGL. In my case there were two symlinks but one was wrong.
libGL.so.1 must point to just one of them (I can't remember which is the exact name but it must not contain the word wrapper). Try making some symlinks with
[root]# ln -s /usr/lib/..Corect lib... /usr/lib/libGL.so.1
I think that's the right name but I'm not sure (I don't know'em by heart and I an not in Linux)

I had the same problem...
Here is how i solved it (obviously not by my self)
you need the latest drivers and the kernel source

init 3
su
go to the dir where you ve dl the driver...
rpm -Uhv --force name of driver mine is fglrx-4.3.0-3.9.0.i386.rpm
then run
fglrxconfig and use external AGP_Gart ----)yes
edit
/etc/modprobe.conf and add this line
"install fglrx /sbin/modprobe --ignore-install fglrx && { /sbin/modprobe nvidia_agp; /bin/true; }"

/etc/rc.d/rc.modules and add this line
"/sbin/modprobe fglrx"
REMEMBER do this like ROOT
init 5
restart the system...

it really helped me :
C++ Boars method

From what I heard ATI drivers for linux are not that great but the next version of them will be better.

On a side note Nvidia GF 4 + NForce 2 works great.