[Zope] Import/Export Problem with Tracker

I want to export a tracker product from one Zope to another. (2.4 to 2.5) Exporting works, but i have got a problem importing the tracker to the new Zope. Always when I try to import my file(Tracker.zexp). I get the following error-message: Zope Error Zope has encountered an error while publishing this resource. Error Type: ImportError Error Value: No module named Splitter Does somebody know how to get the thing to work ?