Steps to reproduce it

1. Fresh Jenkins installation (using Jenkins ver. 2.0-rc-1)
2. Create a new GitHub Organization
3. As owner we choose GH2 (there is a GitHub User Account with this name)
4. Save the job

Result in the console output

Started
Consulting GitHub Organization
Connecting to github.com with no credentials, anonymous access
FATAL: GH2 does not correspond to a known GitHub User Account or Organization
Finished: FAILURE