NO JOKE.....LOL the camera fell off the back of it !!!
Was taking photo's at a local Airshow, turned camera from landscape to portrait for a vertical shot and the camera disconnected from the lens.... fortunately I had straps on both the lens and camera.... " LUCKY I hear you say.... well not quite, I ended up with the camera in my right hand and 8 lb of white lens swung down and hit me in the balls.. !!
Bulls$%t, I hear you say, NO LIE, this happened.
So there I am slightly cross legged, trying to catch breath and trying to make it look like nothing had happened !! ( much to the amusement of the crowd, especially the photographers who had prior picked me as the smart ass with more money than sense )
Anyway, the point is, after I had regained some dignity and some F-111's appeared to shift attention from me, the lens did become unlocked a couple of times in the day........ I had noticed my 100-400 felt loose on the bayonette right back when I first got it, but it never unlocked.
Has anyone out there got the same condition or maybe the locking mechanism on the camera is defective ??