Arrows and Boats overpass pistons, pressure plates, etc...

Well, i was trying to make a redstone thingy but, it was necessary to shot to a sticky piston, well, when i shot the sticky piston, something not normal happened...

http://oi40.tinypic.com/icjs01.jpg

Ok, i shoted the arrow and now the arrow (or half of the arrow) is in that place of the sticky piston, just like i wanted.

But then, when the sticky piston was up (that system that i made was to make the sticky piston go up and down ) , when the sticky piston was up, the arrow just overpass the sticky piston

http://oi44.tinypic.com/28j8v93.jpg

Well that su*** because i need the arrow in the sticky piston going up and down but, it doesn't. This is a bug , i think this bug didn't appear in 1.5.2 or 1.6.2 . Please fix it because with that system i can make something EPIC

PS : sorry for my bad english.
PPS: Could you make this fixed for 1.7.3 please (and for the 1.8,1.9 ...)? I need it fixed for what im trying to do .