Mac: Native drag and drop: Faulty file paths after native file with umlaute was dropped

I know native drag and drop is not currently not supported on Mac OS X, but I found a workaround using a drag-exit-eventhandler in my application. Nevertheless this is not not the problem :) If I try to drag some files which contain umlaute, then I got from "event.getDragboard().getFiles()" files with wrong file paths. Note, this only happens with umlaute. My current workaround is: "new File(new URI("file://" + transferedFile.getAbsolutePath()))".