Only 1 of multiple obsoletes mentioned in pre-transaction prompt

I just rolled myself a package of perl-IO-Compress, which
obsoletes/provides perl-Compress-Zlib, perl-IO-Compress-Base,
perl-IO-Compress-Zlib, and perl-IO-Compress-Bzip2. The resulting "yum
update" looked like this:

# yum update
city-fan.org                                                                                                         | 2.7 kB     00:00 ... 
city-fan.org/primary_db                                                                                              | 244 kB     00:00 ... 
Setting up Update Process
Resolving Dependencies
--> Running transaction check
---> Package perl-IO-Compress.noarch 0:2.023-1.fc12 set to be updated
--> Finished Dependency Resolution

Dependencies Resolved

============================================================================================================================================
 Package                              Arch                       Version                             Repository                        Size
============================================================================================================================================
Installing:
 perl-IO-Compress                     noarch                     2.023-1.fc12                        city-fan.org                     209 k
     replacing  perl-IO-Compress-Bzip2.noarch 2.015-1.fc12


Transaction Summary
============================================================================================================================================
Install       1 Package(s)
Upgrade       0 Package(s)

Total download size: 209 k
Is this ok [y/N]: y
Downloading Packages:
Running rpm_check_debug
Running Transaction Test
Finished Transaction Test
Transaction Test Succeeded
Running Transaction
  Installing     : perl-IO-Compress-2.023-1.fc12.noarch                                                                                 1/5 
  Erasing        : perl-Compress-Zlib-2.015-1.fc12.noarch                                                                               2/5 
  Erasing        : perl-IO-Compress-Base-2.015-1.fc12.noarch                                                                            3/5 
  Erasing        : perl-IO-Compress-Zlib-2.015-1.fc12.noarch                                                                            4/5 
  Erasing        : perl-IO-Compress-Bzip2-2.015-1.fc12.noarch                                                                           5/5 

Installed:
  perl-IO-Compress.noarch 0:2.023-1.fc12                                                                                                    

Replaced:
  perl-Compress-Zlib.noarch 0:2.015-1.fc12      perl-IO-Compress-Base.noarch 0:2.015-1.fc12   perl-IO-Compress-Bzip2.noarch 0:2.015-1.fc12  
  perl-IO-Compress-Zlib.noarch 0:2.015-1.fc12  

Complete!


So, as intended, yum replaced the 4 old packages with the new one.
However, the pre-transaction prompt only mentioned one of the four
packages that was getting replaced, which I imagine could result in
some surprises in other circumstances. Shouldn't the prompt list *all*
of the packages that are being obsoleted?

Paul.