this game seems sketchy to me with some fatalities. it's the same with cyber sub...his babality, it just WON'T work for me. maybe 2/10 times. D, B, F, RT, nothing. but if I throw do his fatalities, no issues. i've had it happen with a few other people too. some seem to be MUCH more forgiving than others.
I usually hold down block while doing my fatalites. Give it a try. Of course remember to release block right your gonna hit the button at the end of the motion. --- Best Fight Scene of ALL TIME!! http://www.youtube.com/watch?v=uxkr4wS7XqY
I had a similar problem where someone had a fatality that had to be at jump range but there was a F, F input necessary that would dash me in close... Holding block helped... --- There was a time when the Church ruled the world It was called the Dark Ages