Mac OS X 10.7 / 10.8: movie editing
The reason are two missing images which Apple "forgot" to add to the QTKit framework. We copied these images from MacOS X 10.6, converted them to PNG and added them to the QTKit framework - afterwards the current position and selection was shown correctly.
But there are still 2 things: 1.) the current selection is difficult to see (low contrast between black and dark gray) and 2.) sometimes the current selection is not set correctly. Calling "Select None" in the edit menu before selecting a part of the movie will fix the second problem.
You can download the images at our download area. After unzipping the file, copy the two images to System -> Library -> Frameworks -> QTKit.framework -> Resources.