Just getting started with CS5 and encountering a few changes.
Interesting is that that the .lockState property has been removed from Text Frames. Well Text Frames and a few other items. I suppose that since it is the story of the frame that is locked it makes sense, but why the change now?
.checkIn () & .checkOut ()
Similar to the .lockState, the .checkIn and .checkOut methods have been moved to the story. The easy fix in all of these cases is to insert .parentStory in front of .lockState or .checkOut() or .checkIn().