The Current VIs Parents Ref.vi opens a reference to a VI and doesn't close it (obviously, because otherwise the ref in the output would not be valid anymore). I think however the help should note that the returned ref should be closed by the caller after he's done with it.
When occasionally calling this VI in your app, it shouldn't be a real problem, but I recently had an application which seemed to have a memory leak, and after letting the Desktop Execution Trace Toolkit take a peek at it, I found that it was caused by Current VIs Parents Ref being called somewhere in the call-chain of a very tight loop (20ms). Closing the ref when done with it fixed this.
Not really a bug this, but expected behaviour that should be clearly noted in the help I think, hence the post here instead of bugs forum.
This was noted in LV2010SP1 btw.
See LAVA Thread: http://lavag.org/topic/14083-memory-leak-in-current-vis-parents-refvi/
Fixed in SVN revision: 1404