I have to say i don't agree with the idea that you are either sub or Dom/me, in the same sense that i don't believe you are either gay or straight.
I am bisexual and believe in falling for the person and not the gender.

I am also a switch which is possibly connected to my bisexuality. I cannot and do not wish to dominate men, with men i am strictly submissive. However i enjoy being dominant with women... go figure!