It means that the file /usr/x11r6/lib/libgl.so.1.2 is already present in the XFree86-libs package,
and that the ATI drivers will overwrite it. Since this is probably what you want, back up the
original file, and use the --force flag to the rpm command to install the ati rpm.
 
>p.s. how do i install amsn if its .tar ?
 
Wild guess: tar xvf xxx.tar; ./configure; make; make install

If you're feeling up to it, you can try installing the ATi drivers by hand using a variation on the method outlined here. Mandrake most likely won't have the rpm2targz utility (it was written by Slackware IIRC) but the Linux from Scratch guys have thoughtfully made it available on one of their sites. Just download the bz2ball, uncompress it into a temporary directory and run the supplied install script. You also won't have the Slackware pkgtool so instead, change to the root directory and just untar the fglrx tarball into there.
 
Lastly, you'll need the source of the exact kernel that you're running. If you selected the Kernel Development group when you installed Mandrake then this most likely would have been done for you otherwise load up whatever package management tool you use and hunt around for a package with a name like kernel-source-whatever and install it.
 
Once that's done you should be able to just change to /lib/modules/fglrx and run to the two installation scripts (build_mod/make.sh and make_install.sh) to compile and install the fglrx modules. Assuming that completes successfully you can then run the ATi fglrxconfig tool to make a customised XF86Config-4 file using the fglrx modules.
 

Quote:p.s. how do i install amsn if its .tar ? anyone know how to tweak mtu or rwin on linux? 
You don't . You download Gaim and use that instead, it's much better.

You may want to check out the fglrx drivers. If you use SUSE the link is:
 
ftp://ftp.suse.com/pub/suse/i386/supplementary/X/XFree86/ATI/suse90/fglrx/3.2.8/