I downloaded the CentOs 6.4 x86_64 dvds and wrote them to dvds.
No matter what I select for installation choices, I always get
the installer finds multiple versions of the same package and quits.

ED.g. aspell, different levels of the same pkg, and many others.

I tried just the default for all of the choices, desktop, minimal desktop, web server, software development workstation, e.g. and it always fails with conflicts.

I tried deleting as much as I could from the options, and it still
fails.

The funny thing is that I ran into the same thing with the 6.2 install DVDs, even though I used them to install just last week, and then upgraded to the latest level.

The only difference that I can think of is that maybe I was not connected to the internet when I did the prior install that worked.

Could that make a difference?

I also tried the net install CD, and it gave the same results.

Sometimes it's hard to see the obvious!

I was not formatting /var, as it had mysql data in it.
Now it is clear that var holds packages as well, and these were causing the problem.

That was the difference, not formatting /var.

Of course, everything is obvious after the fact!

Odd i have never had this issue with CentOS

Are you trying to "upgrade" and existing centos 6.3 install ?
Or is this a new fresh install on a newly reformatted drive ?

now there "can" be issues if you pick and choose software to install
the normal "default" desktop install is recommended ,then after the system is set up and running then remove unneeded software .


burn the "CentOS-6.4-x86_64-bin-DVD1.iso " to dvd
the second dvd is not needed 99% of the time

if an upgrade then put a check in the " upgrade an existing install"
if not
then just the default desktop install