Uhm... If you have got the Qt-4.5.2 why you have the reference to Trolltech.
Now Qt is develop by Nokia.
Anyway you need to check if Qt Creator was compiled on the same Qt version you use for your library.
Help\About Qt Creator
Also try if you have this path: lib/qtcreator/plugins/
All the plug-in I can see in my QtCreator are in that subdir.
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