I was removing the lens hood of my year old Oly 12-40mm F2.8 so as to take a flash picture when it fell off in my hand into three pieces,with another small piece lost under a table. This is not the first time I have had trouble with Oly lens hoods. I no longer use my factory approved hood on my Oly 17mm F1.8 because the screw that supposedly tightens it on does no such thing. A similarly designed metal hood for my 75mm Oly 1.8 had a similar problem,though it was an off brand cheap version. The quite expensive factory version works well. The 12-40 zoom is plastic with metal springs while the other two are all metal with a band that tightens with a screw. Neither appears to be well designed. Has anyone else had these problems?