Torches can be placed on leaves on fast graphics,not fancy. Once placed on leaves,change to fancy graphics and the torch will still be there.

Cannot confirm, did you placed the torch directly on top of the leaves block, or do you used any kind of trick?
And also, did you have "Fast" selected when starting the game, or allways, or only switched right before placing the torch?
And what kind of leaves were it?

i placed them on the side of the leaf block.
i did not use any mod or texture pack
fast graphics when starting the game
oak leaves

Cannot confirm. Torch is not placable.

Please provide a screenshot with debug screen enabled.