This is what I get in the Ruby Console:
old_require "C:/Program Files (x86)/Google/Google SketchUp 8/Plugins/ROUNDCORNER_Dir_23/RoundCorner_Algo.rb"
old_require "C:/Program Files (x86)/Google/Google SketchUp 8/Plugins/ROUNDCORNER_Dir_23/RoundCorner_AlgoRound.rb"
old_require "C:/Program Files (x86)/Google/Google SketchUp 8/Plugins/ROUNDCORNER_Dir_23/RoundCorner_AlgoSharp.rb"
old_require "C:/Program Files (x86)/Google/Google SketchUp 8/Plugins/ROUNDCORNER_Dir_23/RoundCorner_Tool.rb"
Error: #<NameError: undefined method action__mapping' for class Module'>
C:/Program Files (x86)/Google/Google SketchUp 8/Plugins/LIBFREDO6_Dir_47/Lib6Plugin.rb:127:in method' C:/Program Files (x86)/Google/Google SketchUp 8/Plugins/LIBFREDO6_Dir_47/Lib6Plugin.rb:127:in launch_action'
C:/Program Files (x86)/Google/Google SketchUp 8/Plugins/ROUNDCORNER_Dir_23/bootstrap_RoundCorner.rb:143:in launch_action' C:/Program Files (x86)/Google/Google SketchUp 8/Plugins/ROUNDCORNER_Dir_23/bootstrap_RoundCorner.rb:159:in startup'
C:/Program Files (x86)/Google/Google SketchUp 8/Plugins/LIBFREDO6_Dir_47/Lib6Plugin.rb:1092:in call' C:/Program Files (x86)/Google/Google SketchUp 8/Plugins/LIBFREDO6_Dir_47/Lib6Plugin.rb:1092:in command_invoke'
C:/Program Files (x86)/Google/Google SketchUp 8/Plugins/LIBFREDO6_Dir_47/Lib6Plugin.rb:1074:in build_config_commands' C:/Program Files (x86)/Google/Google SketchUp 8/Plugins/LIBFREDO6_Dir_47/Lib6Traductor.rb:1061:in call'
C:/Program Files (x86)/Google/Google SketchUp 8/Plugins/LIBFREDO6_Dir_47/Lib6Traductor.rb:1061:in `add_command'