I have never shut-off the camera while changing lenses with VR, OS, IS on at all times. Most of my lenses are VR, OS, IS. Never a single problem and I have done it thousands of times. As another poster here pointed out that more dust gets in from zoom lenses than from charged CMOS. Plus before you put rear cap on dust gets in the lens on the rear element and then due to turbulence of mirror that dust gets on everything. And I know that as soon as you disconnect the lens electrical contacts become inactive. It is build in to every camera otherwise every one would have problems. Just think about it, if you clean the camera's sensor you need to remove the lens while camera is on. Right?