How to find yum (rpm) duplicate packages?

[Daniel B. Thurman]

Paul W. Frields wrote:
> On Thu, Mar 26, 2009 at 11:04:41AM -0700, Daniel B. Thurman wrote:
>   
>> I am unable to find yum/rpm instructions on how to
>> find/locate duplicate packages that might be on my
>> system.
>>
>> Does anyone know how this is done?
>>     
>
> Install the 'yum-utils' package. It includes the 'package-cleanup'
> utility that does what you want.
>
>   
Thanks for the tip!

Howevcr, I ran into this problem:
==================================================
# package-cleanup --cleandupes
Setting up yum
Loaded plugins: fastestmirror, refresh-packagekit
Loading mirror speeds from cached hostfile
I will remove the following old duplicate packages:
2:lam-libs-7.1.2-11.fc9.i386
postgresql-pgpoolAdmin-1.0.0-7.fc8.noarch
Is this ok [y/N]: y
/usr/lib/lam/lam.ld.conf has not been configured as an alternative for 
mpilibs32
error: %preun(lam-libs-7.1.2-11.fc9.i386) scriptlet failed, exit status 2
=====================================================

So, how can I remove lam-libs?