Hiragana W/ Dvorak Input



I am using dvorak layout in mac os x tiger. When i enable kotoeri layouts (hiragana/katakana) it expects qwerty as input for the construction of hiragana/katakana phonems. For example "ka" would make a hiragana symbol on the screen if hiragana was enabled. and indeed it makes one, but i want in dvorak input. I searched in evey possible way: irc channels like #macosx, #dvorak and other and no one is in my situation or knows an answer. i tried google and this site and nothing. is there really a solution? that wouldn't include changing back to qwerty, no thanks.
if not i would want to edit the damm base layout it uses to whatever i want.

Thanks in advance for the available help.