That is odd. My sensors pick up even high kerbs pretty well and will give a nice rapid beeping as I'm nearing the kerb.
My sensors definately detect obsticles <1ft high as we have a wooden planter on our drive at about that height I reverse towards.
What I also like is that the outer most sensors are on the corners of the car and can detect obsitcles off to the side, further reducing the risk of bumping into things.
As far as the bins go, I myself have reversed into our wheely bins in my old Civic and managed to cave in a large part of the tail gate
I have reversed quite quickly (as a test) towards a wall and stopped about 12" away, before the sensors even detected it. They then sounded their 'getting close!' super rapid beeping mode. I can easily see someone being able to hit something before the beepers gave their warning. The moral is only reverse dead slow and you will be fine!
