Firstly, I just joined last week, so hello everyone. I was hoping not to have to come crying too soon, but I haven't been able to find any discussion of my problem here, nvidia linux forum or google.
Using yum to install mplayer finds that the Mesa-libGL is a dependency. Okay, I installed anyway, knowing there was a conflict with the nvidia drivers. Trying to open Doom 3 from a
terminal, it crashes with an error to the effect that there is a conflict between video card (BFG
6600 GT OC) and driver in use. Checking /etc/xorg.conf, I found that the "load dri" had been
added back. Even after removing it the problem persisted. I saw no other obvious changes.
I reinstalled Fedora Core 3.
I would really like to have mplayer. Can any please help with this?

I also have had to address a conflict with libGL, though honestly I don't know what package causes the conflict. Mesa is a good bet, I suppose.

What does your /var/log/nvidia-installer have to say about this conflict? Did it report a failed sanity check? Do OpenGL programs such as glxgears run OK, or do they run slowly?

In my particular case, libGL.so.1 was a symlink in /usr/local/lib that pointed to libGLU.so.1.3.501 which was also in /usr/local/lib. My Nvidia driver, /usr/lib/libGL.so.1.0.6629 is the one I wanted, so I deleted the symlinks libGL.so and libGL.so.1 in /usr/local/lib and replaced them with symlinks of the same names pointed to the Nvidia driver. I also have symlinks of the same names in /usr/lib pointed to the Nvidia driver. This solved my problem, and there has been no evidence at all of problems with Mesa or anything else.

Over the last few days, I have upgraded several dozen packages from the Mandrake 10 versions to the Mandrake 10.1 versions, and one of them set the links back to eh wrong driver. I noticed this immediately from display performance. I changed the links back, and everything works fine again.

Appreciate the quick reply Jimi18. I will try your method after work and post my results.

the nvidia installer trys during the install to clean things up.
so another thing to do is to reinstall nvidia driver after things go south