Validation failed: Name Operating system version already exists, Title has already been taken

I have three products for Scientific Linux version 6 (64 bit).

SL62x64 - update 2
SL63x64 - update 3
SL65x64 - update 5

Under each product, I have an OS repo, which synchronize with:

http://ftp.scientificlinux.org/linux/scientific/6.2/x86_64/os/
http://ftp.scientificlinux.org/linux/scientific/6.3/x86_64/os/
http://ftp.scientificlinux.org/linux/scientific/6.5/x86_64/os/

The last two of these repos complain about:

Validation failed: Name Operating system version already exists, Title has
already been taken

The repos do synchronise.

Interestingly, I also have two products for Scientific Linux version 6 (32
bit).

SL62x64 - update 2
SL63x64 - update 3

Again, under each product, I have a respective OS repo, which synchronize
with:

http://ftp.scientificlinux.org/linux/scientific/6.2/i386/os/
http://ftp.scientificlinux.org/linux/scientific/6.3/i386/os/

But I don't get the same problem.

The output from the Operating System page for SL is attached.

Any thoughts?