Description of problem:
When installing pam on a biarch system all kinds of files in /etc/pam.d and
/etc/security and recently /var/log/{faillog,tallylog} create .rpmnew files. 
This is most probably because of different time stamps of the files in the two RPMs.

Version-Release number of selected component (if applicable):
pam-0.99.6.2-3.fc6

How reproducible:
always

Steps to Reproduce:
1.install both RPMs on biarch system
2.
3.
  
Actual results:
lots of .rpmnew files

Expected results:
no .rpmnew files unless really necessary

Additional info:
The solution for this is to use

  touch -r REFFILE $RPMROOT/etc/pam.d/NEWFILE

for all the affected files NEWFILE and where REFFILE is a file in the source
tree which isn't touched during the build process.