The default mappings will be stored as .automap files. There are two sets, the factory defaults and user defaults.

On the Mac:

factory: /Applications/AutomapServer.app/Contents/Resources/Mappings/"pluginname".automap

user: your_home_folder/Library/Application Support/Novation/Automap Universal/Mappings/"pluginname".automap

On the PC:

factory: automap_universal_install_folder/Mappings

user: (system drive):Documents and Settings/your_user_name/Application Data/NovationAutomap Universal/Mappings

User mappings override factory mappings, so if you want to revert to the factory mapping just delete the user mapping If there is no factory mapping the plug-in will revert to the order it lists it's parameters.