Akuma's "firecracker" (hey, thats what we called it back in the day in the rough, tough arcades in yorkshire) is pretty hard to do in the xbla version of MVC2.
I used to tap LP, LP, F + LK literally together then HP in the arcades and it came out no problem.
I have nailed it only a couple of times on xbla, the first time nailing it took a while, but the second time came not long after the 1st.
At a steady pace (no need to input it too fast) i did LP, LP, F (by itself) LK, HP.
Another problem is that the move hardly has any distance in MVC2 (Akuma only slides across the screen for like 12 feet then its gone)
@ Graham
You should get it buddy, your may think your team is a bit on the cheap side, but then again so is probably 70% of other peoples teams.
(Spidey, Cable and say Ironman for example)