I have a Dell Optiplex 980 with a Radeon HD 6450 card which was working 
fine with the elrepo fglrx-x11-drv and kmod-fglrx packages until I 
recently upgraded to kernel 2.6.32-573.12.1.el6.x86_64 and fglrx 
versions 15.12-1.  Now when I move a window on the screen, the content 
isn't erased from the old location, leaving a trail of ghosts behind.
This happens with more than one window manager (fvwm, icewm, fluxbox), 
so I think its an X problem, rather than a window manager bug.

The guys at elrepo were very responsive, but they didn't have the 
problem on their own machines, and it's not really their software - it 
is closed source from ATI - and they have run out of guesses for what to 
try.  I have tried installing ATI's own rpm and that behaves the same 
way.  I've filed a bug on the unofficial ATI bugzilla, but don't have 
great hopes there.  I'm wondering whether anyone here has ever seen 
symptoms like these.  Using the radeon driver gets me a mostly usable 
system, but there is some stuff that says it won't work without glx.

Stephen Isard