Thanks for responding. I really don't know why I have the problem my computer is a Dell computer with the standard parts. I am not sure that your fix will work for me. I am using the computer remotely and am still looking for a solution.
Thanks Shoshana
I just upgraded to CentOS 6.9 and my problem went away. Xorg now started on my machine with the MACH64 video chip. Hooray for our side.
Bob