Title says it all, I don't really know the whole story... I haven't been using the camera much lately. But I was taking pictures and things just didn't seem very sharp so I took off my lens and started examining everything but I didn't even look at the sensor which I instinctively covered with the cap as I removed the lens. My wife walks up to me as I was cleaning the back of the lens (which had a smudge) and told me that she smudged the "other thing" on the camera side and not to worry because she cleaned it... Ugh. Well basically the sensor does look clean and she swears she did it lightly with "feather like" swipes...but I'm freaking out because I know the image stabilization is fragile and the sensor has coatings on it etc... How should I check to make sure everything is working properly... Or isn't?