Felix Conrad has a nice series of mini lectures set up on his site where he systematically and very logically examines the theory of Autogynephilia and pokes enough holes in it to make it even more of a Swiss cheese than it already was (not that this is so difficult).
Felix touches on the same fallacy of logic as well as the basic missing science which makes the theory a pure fantasy of speculation. If you read the whole thing through you will understand what I mean. It, of course, acknowledges arousal but discounts it as the origin of gynephilic transsexualism. Instead it puts it where it belongs which is as a symptom of something bigger and more complex.
He goes even further in acknowledging that you can have two typologies separated by orientation but that even that is circumstantial and is just another filter through which the condition must pass.
I highly recommend you read the whole thing which can be found at this link