Description of problem:
yumdownloader does not download Source RPMs when (SRPM) provided '--source' flag

Version-Release number of selected component (if applicable):
# yumdownloader --version
yumdownloader - 1.0 (yum - 3.2.29)

How reproducible:
Reproduced on one system, confirmed by at least one other person.

Steps to Reproduce:
(Using GCC as an example)
1.  install yumdownloader, if not already installed
2.  type 'yumdownloader --source gcc'
  
Actual results: It says there is no Source RPM, and nothing to download
# yumdownloader --source gcc (Example From RedHat '6Server')
Loaded plugins: product-id, refresh-packagekit, rhnplugin
No source RPM found for gcc-4.4.4-13.el6.x86_64
No source RPM found for gcc-4.4.5-6.el6.x86_64
Nothing to download
# 

Expected results: This it downloads a Source RPM (example from working CentOS5
# yumdownloader --source gcc
Loaded plugins: fastestmirror
Loading mirror speeds from cached hostfile
 * base: mirror.5ninesolutions.com
 * extras: mirrors.usc.edu
 * updates: mirror.5ninesolutions.com
gcc-4.1.2-50.el5.src.rpm                                 |  37 MB     00:03
#

Additional info:
*Also tried with enabled/disabled repositories; example: (though I've been told this shouldn't make a difference)

[rhel-source]
name=Red Hat Enterprise Linux $releasever - $basearch - Source
baseurl=ftp://ftp.redhat.com/pub/redhat/linux/enterprise/$releasever/en/os/SRPMS/
enabled=1
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-redhat-release

*Works without --source flag
# yumdownloader gcc
Loaded plugins: product-id, refresh-packagekit, rhnplugin
gcc-4.4.5-6.el6.x86_64.rpm  

*Fails with packages aside from GCC
# yumdownloader --source gedit
Loaded plugins: product-id, refresh-packagekit, rhnplugin
No source RPM found for 1:gedit-2.28.4-3.el6.x86_64
Nothing to download

*Confirmed existance of src.rpm files via ftp to ftp.redhat.com
# ftp ftp.redhat.com
Connected to ftp.redhat.com.
220 Red Hat FTP server ready. All transfers are logged. (FTP) [no EPSV]
530 Please login with USER and PASS.
530 Please login with USER and PASS.
KERBEROS_V4 rejected as an authentication type
Name (ftp.redhat.com:root): anonymous
331 Please specify the password.
Password:
230 Login successful.
Remote system type is UNIX.
Using binary mode to transfer files.
ftp> cd /pub/redhat/linux/enterprise/6Server/en/os/SRPMS
250 Directory successfully changed.
ftp> ls gcc*
227 Entering Passive Mode (209,132,183,61,163,217).
150 Here comes the directory listing.
-rw-r--r--    4 ftp      ftp      52214716 Aug 17  2010 gcc-4.4.4-13.el6.src.rpm
-rw-r--r--    5 ftp      ftp      52113813 Apr 21 20:28 gcc-4.4.5-6.el6.src.rpm
226 Directory send OK.
ftp>