Back "shoryuken" motion cannot be "shortcuted"? (PC)

Greatins everyone.
This is my first post here. I just registered a few minutes ago to make this post.
I’ve tryed to look for an anwser but couldn’t find anything.
I hope I’m posting this on the correct spot.

Im a casual SF4 player. I have bought the Arcade Edition for the PC (i do not own any “new” console) and I’m very happy with it.
I’m using a pad to play. (A logitech coordless rumblepad 2 ).
I notice that i cannot “shortcut” (not sure if its called “shotcut”) a back shoryuken movement.
Examples:
I can do a foward -> downfoward->foward+punch and the shoryuken comes out.
however i CANNOT do a backwards->downbackwards->back+puch and the move doesn’t come out.

Pictures:
Check out the Ibuki atack: doing a foward shoriuken movement

http://dl.dropbox.com/u/14303393/Ibuki%20shk.jpg

Now the back shoryuken movement.

http://dl.dropbox.com/u/14303393/back%20shk.jpg

Doesn’t work

Is this a pc issue? Or the console has the same problem?

Thanks for any response.

AFAIK the problem is ibuki, she has so much motion you can’t shortcut them all.
Try with Fei Long which DP motion is 421, it should work.

Hey there.
I tryed T. Hawk attack and it doesn’t work either :confused:

But then i read your post and you are right Fei Long atack IS working.

Thanks for the quick anwser

yeah it just depends on the move
each part of the input can be set to require only that direction to be pressed, or allow that direction + any direction
so a normal srk is foward+ any, down+any, foward+down
but ibuki’s command jump is forward only, down only, forward+down
like how balrog can do a dash punch when holding down but guile can’t do a sonic boom