Not quite a failed ejection, but it is on the ejection site and an amazing story. I think it was a canberra lost control at about threshold height, one of the backseaters (I think three people were on board) ejected. The backwards velocity cancelled out the forward of the aircraft, the seat seperated and he landed on his feet at a slight jog.
I really should have re-read the story before posting this though...
the story is here:
http://www.ejectionsite.com/
Under aircrew stories on the left hand side, Canberra 1966.
My version is complete fabrication, the actual version is astounding.