Description of problem:
Trying package-cleanup --oldkernels:

Version-Release number of selected component (if applicable):
yum-utils-1.1.7-1.fc7

How reproducible:
Always.

Steps to Reproduce:
1.Trying package-cleanup --oldkernels
2.
3.
  
Actual results:
Setting up yum
I will remove the following 1 kernel related packages:
kernel-devel-2.6.23.1-10.fc7
Is this ok [y/N]: y
/usr/bin/package-cleanup:312: DeprecationWarning: returnHeaderByTuple() will go
away in a future version of Yum.

  hdr = my.rpmdb.returnHeaderByTuple(kernel)[0]
Traceback (most recent call last):
  File "/usr/bin/package-cleanup", line 402, in <module>
    main()
  File "/usr/bin/package-cleanup", line 371, in main
    removeKernels(my, opts.kernelcount, opts.confirmed, opts.keepdevel)
  File "/usr/bin/package-cleanup", line 317, in removeKernels
    my.populateTs()
  File "/usr/lib/python2.5/site-packages/yum/depsolve.py", line 231, in populateTs
    self.ts.addErase(txmbr.po.idx)
  File "/usr/lib/python2.5/site-packages/yum/packages.py", line 682, in __getattr__
    return self.hdr[thing]
KeyError: 'unknown header tag'


Expected results:
kernel-devel-2.6.23.1-21.fc7 has been removed

Additional info: Directly using "yum erase  yum erase
kernel-devel-2.6.23.1-10.fc7" is performed well:
yum erase kernel-devel-2.6.23.1-10.fc7
Setting up Remove Process
Resolving Dependencies
--> Running transaction check
---> Package kernel-devel.x86_64 0:2.6.23.1-10.fc7 set to be erased
--> Finished Dependency Resolution

Dependencies Resolved

=============================================================================
 Package                 Arch       Version          Repository        Size 
=============================================================================
Removing:
 kernel-devel            x86_64     2.6.23.1-10.fc7  installed          15 M

Transaction Summary
=============================================================================
Install      0 Package(s)         
Update       0 Package(s)         
Remove       1 Package(s)         

Is this ok [y/N]: y
Downloading Packages:
Running rpm_check_debug
Running Transaction Test
Finished Transaction Test
Transaction Test Succeeded
Running Transaction
  Erasing   : kernel-devel                 ######################### [1/1] 

Removed: kernel-devel.x86_64 0:2.6.23.1-10.fc7
Complete!