Quote Originally Posted by DJZen
Why do I have this sneaking suspicion that you're making that up?
He is, the manual makes no remarks to a classes gender. The only reference to gender in the manual is this:

Keep in mind that a character can change only to the advanced version of his or her starting class.
I believe the characters are sexually ambiguous, so that the player can choose their gender. The only exception is the monk in DoS, due to his clothing.