Microsoft has just updated the following KB Article:
Guided walkthrough for troubleshooting ConfigMgr 2012 software update synchronization issues
Summary:
A Guided Walkthrough is available that helps identify and resolve issues that relates to Software Update synchronization in System Center 2012 Configuration Manager (ConfigMgr 2012 or ConfigMgr 2012 R2).
Full details at:
https://support.microsoft.com/en-us/kb/2995743