Description of problem:
When a system is subscribed to empty channel one is not able to operate with yum. For example calling 

# yum list available

ends with error

Error: Cannot retrieve repository metadata (repomd.xml) for repository: my_soft_rhel5_32b_x86. Please verify its path and try again

Steps to Reproduce:
1. Create an empty base channel
2. Create an empty child channel and bind it to the base one above
3. Register a client to the child channel (or alter existing one)
4. Run yum on the client
  
Actual results:
The above error occurs.

Expected results:
Working yum client