Description of problem:

When one does a yum update on a specific package ABC, yum searches for updates
for packages (say XYZ) that require the installed ABC version-release. It is
expected that yum would do a search for XYZ updates for all available archs, but
it does not.

Version-Release number of selected component (if applicable):
3.0.1-5.el5

How reproducible:
Always

Steps to Reproduce:
To reproduce on a 64-bit installation of RHEL5:

1. Install an older version (than the one in rhn) of postgresql (only 64- bit
available) and postgresql-devel (32- and 64- bit). The RHEL5 base DVD has older
versions of these.
2. Subscribe to rhn and run 'yum update postgresql'
  
Actual results:
Yum exits with an error:

Error: Unable to satisfy dependencies
Error: Package postgresql-devel needs postgresql = 8.1.4-1.1, this is not available.

The reason for the above error is that the yum update command causes yum to pack
only postgresql and postgresql-devel (64-bit) in the transaction set. This
leaves the 32-bit postgresql-devel, which needs an older version of postgresql,
still on the system.

Expected results:
Upgrade should succeed, with the new upgrade bringing in the new postgresql and
the new 32- and 64- bit postgresql-devel packages