When I first bought this lens new several years ago, I thought it performed very well. I have not had much opportunity to use this lens much. After the first 2-3 times with good results, I have been dissatisfied with my performance with the lens. Please note how I blame myself as the user, not the lens. I have not used the lens for awhile. I recall when I first used the lens, the VR would lock on and kind of vibrate, with further pressure on the shutter release the shutter would activate. I maybe having an Alzheimer's moment, as that is how I recall the lens working. Now the lens just seems to focus with VR not locking on or vibrating. Am I rememberig wrong the use of the VR? Do you think it is a problem with lens, my D300 or the photographer? How would you go about determining if the VR is working properly?