"Wrong Architecture" when loading plugins on Mac

gistfile1.txt

  @javascript
  Scenario: Creando Person nuevo                    # features/facebook.feature:4
    When I go to the facebook test page             # features/step_definitions/web_steps.rb:23
    When I follow the non link "#curtain-centerpic" # features/step_definitions/web_steps.rb:217
2011-10-24 13:15:26.622 webkit_server[3040:903] Error loading /Library/Internet Plug-Ins/DirectorShockwave.plugin/Contents/MacOS/DirectorShockwave:  dlopen(/Library/Internet Plug-Ins/DirectorShockwave.plugin/Contents/MacOS/DirectorShockwave, 262): no suitable image found.  Did find:
	/Library/Internet Plug-Ins/DirectorShockwave.plugin/Contents/MacOS/DirectorShockwave: mach-o, but wrong architecture
2011-10-24 13:15:26.684 webkit_server[3040:903] Error loading /Library/Internet Plug-Ins/npgtpo3dautoplugin.plugin/Contents/MacOS/npgtpo3dautoplugin:  dlopen(/Library/Internet Plug-Ins/npgtpo3dautoplugin.plugin/Contents/MacOS/npgtpo3dautoplugin, 262): no suitable image found.  Did find:
	/Library/Internet Plug-Ins/npgtpo3dautoplugin.plugin/Contents/MacOS/npgtpo3dautoplugin: mach-o, but wrong architecture
2011-10-24 13:15:26.732 webkit_server[3040:903] Error loading /Library/Internet Plug-Ins/Flip4Mac WMV Plugin.plugin/Contents/MacOS/Flip4Mac WMV Plugin:  dlopen(/Library/Internet Plug-Ins/Flip4Mac WMV Plugin.plugin/Contents/MacOS/Flip4Mac WMV Plugin, 262): no suitable image found.  Did find:
	/Library/Internet Plug-Ins/Flip4Mac WMV Plugin.plugin/Contents/MacOS/Flip4Mac WMV Plugin: no matching architecture in universal wrapper
2011-10-24 13:15:26.735 webkit_server[3040:903] CFPropertyListCreateFromXMLData(): Old-style plist parser: missing semicolon in dictionary.
2011-10-24 13:15:26.735 webkit_server[3040:903] CFPropertyListCreateFromXMLData(): Old-style plist parser: missing semicolon in dictionary.
2011-10-24 13:15:26.762 webkit_server[3040:903] Error loading /Library/Internet Plug-Ins/googletalkbrowserplugin.plugin/Contents/MacOS/googletalkbrowserplugin:  dlopen(/Library/Internet Plug-Ins/googletalkbrowserplugin.plugin/Contents/MacOS/googletalkbrowserplugin, 262): no suitable image found.  Did find:
	/Library/Internet Plug-Ins/googletalkbrowserplugin.plugin/Contents/MacOS/googletalkbrowserplugin: mach-o, but wrong architecture
plugin,NP_Initialize start
plugin,NP_Initialize end
plugin,NP_GetEntryPoints start
Private_Initialize
plugin,NP_GetEntryPoints end
2011-10-24 13:15:26.818 webkit_server[3040:903] Error loading /Library/Internet Plug-Ins/QuickTime Plugin.plugin/Contents/MacOS/QuickTime Plugin:  dlopen(/Library/Internet Plug-Ins/QuickTime Plugin.plugin/Contents/MacOS/QuickTime Plugin, 265): no suitable image found.  Did find:
	/Library/Internet Plug-Ins/QuickTime Plugin.plugin/Contents/MacOS/QuickTime Plugin: no matching architecture in universal wrapper
2011-10-24 13:15:26.859 webkit_server[3040:903] Error loading /Library/Internet Plug-Ins/Flash Player.plugin/Contents/MacOS/Flash Player:  dlopen(/Library/Internet Plug-Ins/Flash Player.plugin/Contents/MacOS/Flash Player, 262): no suitable image found.  Did find:
	/Library/Internet Plug-Ins/Flash Player.plugin/Contents/MacOS/Flash Player: no matching architecture in universal wrapper
2011-10-24 13:15:26.867 webkit_server[3040:903] Error loading /Library/Internet Plug-Ins/Silverlight.plugin/Contents/MacOS/agcore:  dlopen(/Library/Internet Plug-Ins/Silverlight.plugin/Contents/MacOS/agcore, 262): no suitable image found.  Did find:
	/Library/Internet Plug-Ins/Silverlight.plugin/Contents/MacOS/agcore: mach-o, but wrong architecture
    Then Ingreso datos del Test User                # features/step_definitions/facebook_steps.rb:1

I am getting the same problems did you figure it out?

Nope.. Not a clue since October-2011. Maybe you can follow the issue on capybara-webkit. thoughtbot/capybara-webkit#157
Some seems to find something thoughtbot/capybara-webkit#157 (comment)