<p>I have a somewhat different take on this problem - and a different (and simpler) solution. The problem - it seems to me - is that the hood is designed to lock and unlock using only one of the two buttons. In the normal hood position (shooting position) the button to the left of the logo (facing the hood from above) is operative. In the reversed position (storage position) the button to the left of the logo (which, since the hood is now reversed, is the button that previously on the right) is operative. If you look carefully at the tabs on the inside of the hood that do the locking you will see why this is so. Note that there are two separate rings, an inner ring and an outer ring. Which way the hood is placed - normal or reversed - determines which tab engages the locking slot on the lens barrel. But either way - normal or reversed - only one button and it's corresponding tab actually perform the locking. The other tab rides outside of the lock slot, completely inoperative. My experience with losing the hood is that it becomes disengaged when the lens barrel accidentally bumps against my body while carrying the camera. In my case, this most frequently happens when I have the hood installed in the normal, "logo upright" position, where the lens body can bump against my leg or side (I'm right handed and carry the camera on the right side, using a Rapid Strap camera strap). The solution for me was simple: Install the lens hood with the logo facing down. In this orientation, regardless of whether the hood is in the normal or storage position, the active button is away from my body, avoiding accidentally bumping the active button and dislodging the hood.<br>
-Wes</p>